Life Adapts to a Volcanic Landscape

Lichens often pioneer new life on Earth. Two plants in one, lichens are composed of an alga and a fungus growing together to their mutual benefit, usually on rock. Hardy and slow-growing, lichens help break down rock to soil-building mineral matter.Eventually their vegetable matter decays, helping to form the first soils that other plants can then use. Tough in the extreme, some lichens can be heated to high temperatures and still be capable of resuming normal growth when returned to viable conditions.

Eventually their vegetable matter decays, helping to form the first soils that other plants can then use. Tough in the extreme, some lichens can be heated to high temperatures and still be capable of resuming normal growth when returned to viable conditions.

Two thousand years after volcanic eruptions subsided, plants and animals still struggle to gain toeholds on this unforgiving lava field. Much of the worldâ€™s vegetation could not survive here at all. Environmental stresses created by scant soil and minimal moisture are compounded by highly porous cinders that are incapable of holding water near the ground surface where plants and other organisms can make ready use of it. Scarce at bestâ€”total average precipitation is between 15 to 20 inches per yearâ€”rainwater and snowmelt quickly slip down out of reach of the plants growing on cinder cones. Summerâ€™s hot, dry winds rob moisture from all living things exposed to them. Whisking across leaves and needles the winds carry away moisture precious to plant tissues. On the side of a cinder cone, summer day temperatures at ground level can be more than 150Â°F.

The secret to survival here is adaptation. Most life forms cope by strategies of either resisting or evading the extremes of this semi-arid climate. To resist being robbed of moisture by winds and heat, a plant may feature very small leaves that minimize moisture loss. To evade heat, wind, and aridity, another plant may grow inside a crevice that provides life-giving shade and collects precious moisture and soil particles. Another plant may spend about 95 percent of the year dormant. It may rush through the germination, sprouting, leafing out, blooming, and fruiting stages and return to the dormancy of its seed stage in just two weeks. The dwarf buckwheat has adapted to life on porous cinders by evolving a root system that may spread out for up to 3 feet to support its aboveground part, which is a mere 4 inches high. This buckwheat only looks like a dwarf because you can not see its roots.

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Water is the limiting factor in plant growth and reproduction both on the lava fields of Craters of the Moon and on the surrounding sagebrush steppe. Plants have developed a combination of adaptations to cope with drought conditions. There are three major strategies:1. Drought tolerancePhysiological adaptations leading to drought tolerance are typical of desert plant species. The tissues of some plants can withstand extreme dehydration without suffering permanent cell damage. Some plants can extract water from very dry soils. Sagebrush and antelope bitterbrush exemplify drought tolerance.Dwarf monkeyflowerBuckwheat2. Drought avoidanceCertain structural modifications can enable plants to retain or conserve water. Common adaptations of this type include small leaves, hairiness, and succulence. The small leaves of the antelope bitterbrush expose less area to evaporative influences such as heat and wind. Hairs on the scorpionweed reduce surface evaporation by inhibiting air flow and reflecting sunlight. Succulent plants such as pricklypear cactus have tissues that can store water for use during drought periods. Other plants, such as wire lettuce, avoid drought by having very little leaf surface compared to their overall volume.3. Drought escapeSome plants, such as mosses and ferns, escape drought by growing near persistent water supplies such as natural potholes and seeps from ice caves. Many other drought escapers, such as dwarf monkeyflower, simply carry out their full life cycle during the moist time of the year. The rest of the year they survive in seed form.Pricklypear cactusFerns

1. Drought tolerancePhysiological adaptations leading to drought tolerance are typical of desert plant species. The tissues of some plants can withstand extreme dehydration without suffering permanent cell damage. Some plants can extract water from very dry soils. Sagebrush and antelope bitterbrush exemplify drought tolerance.

Dwarf monkeyflower

Buckwheat

2. Drought avoidanceCertain structural modifications can enable plants to retain or conserve water. Common adaptations of this type include small leaves, hairiness, and succulence. The small leaves of the antelope bitterbrush expose less area to evaporative influences such as heat and wind. Hairs on the scorpionweed reduce surface evaporation by inhibiting air flow and reflecting sunlight. Succulent plants such as pricklypear cactus have tissues that can store water for use during drought periods. Other plants, such as wire lettuce, avoid drought by having very little leaf surface compared to their overall volume.

3. Drought escapeSome plants, such as mosses and ferns, escape drought by growing near persistent water supplies such as natural potholes and seeps from ice caves. Many other drought escapers, such as dwarf monkeyflower, simply carry out their full life cycle during the moist time of the year. The rest of the year they survive in seed form.

Pricklypear cactus

Ferns

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Lava flowsMost plants cannot grow on lava flows until enough soil has accumulated to support them. The parkâ€™s older volcanic landscapes, where soils are best developed, are clothed with sagebrush-grassland vegetation. On younger lava flows, bits of soil first accumulate in cracks, joints, and crevices. It is in these microhabitats that vascular plants may gain footholds. Narrow cracks and joints may contain desert parsley and lava phlox. Shallow crevices will hold scabland penstemon, fernleaf fleabane, and gland cinquefoil. Deep crevices can support the syringa, various ferns, bush rockspirea, tansybush, and even limber pine. Not until full soil cover is achieved can the antelope bitterbrush, rubber rabbitbrush, and sagebrush find suitable niches. On lava flows soils first form from eroded lava and the slow decomposition of lichens and other plants able to colonize bare rock. These soils can be supplemented by wind-blown soil particles until vascular plants gain footholds. As plants begin to grow and then die, their gradual decomposition adds further soil matter. These soil beginnings accumulate in cracks and crevices, which also provide critical shade and wind protection. Deep crevices provide lower temperatures favoring plant survival.Rubber rabbitbrushSyringaCinder gardensCompared to the lava flows, cinder cones are much more quickly invaded by plants. Here, too, however, volcanic origins influence plant growth. Compared to the relatively level lava flows, steeply sloping cinder cones introduce a new factor that controls the development of plant communities: topography. Here you find marked differences in the plant communities between the north- and south-facing slopes. South-facing slopes are exposed to prolonged, intense sunlight, resulting in high evaporation of water. Because of the prevailing winds, snow accumulates on northeast sides of cones, giving them far more annual water than southwest-facing sides receive. The pioneering herbs that first colonize cinder cones will persist on southwest-facing slopes long after succeeding plant communities have come to dominate north-facing slopes. It is on these north-facing slopes that limber pine first develops in the cinder garden. South-facing slopes may never support the limber pine but may be dominated by shrubs. Unweathered cinder particles range in size from 3 to 4 inches in diameter down to very small particles. They average about Â¼ inch in diameter.CinquefoilWire lettuce

Rubber rabbitbrush

Syringa

Cinder gardensCompared to the lava flows, cinder cones are much more quickly invaded by plants. Here, too, however, volcanic origins influence plant growth. Compared to the relatively level lava flows, steeply sloping cinder cones introduce a new factor that controls the development of plant communities: topography. Here you find marked differences in the plant communities between the north- and south-facing slopes. South-facing slopes are exposed to prolonged, intense sunlight, resulting in high evaporation of water. Because of the prevailing winds, snow accumulates on northeast sides of cones, giving them far more annual water than southwest-facing sides receive. The pioneering herbs that first colonize cinder cones will persist on southwest-facing slopes long after succeeding plant communities have come to dominate north-facing slopes. It is on these north-facing slopes that limber pine first develops in the cinder garden. South-facing slopes may never support the limber pine but may be dominated by shrubs. Unweathered cinder particles range in size from 3 to 4 inches in diameter down to very small particles. They average about Â¼ inch in diameter.

Cinquefoil

Wire lettuce

Ecological conditions at Craters of the Moon are generally so harsh that slight changes can make the difference for the survival of a plant or other organism. Life thrives in many rock crevices that are surrounded by barren exposed lava rock of the same physical composition. These microhabitats provide the critical shade and increased soil and moisture content required for plant survival. Over the years, particles of soil will naturally collect in rock crevices, which also have the effect of funneling precipitation into their depths. Their shade further protects these pockets of soil and water from wind erosion, excessive heat, and evaporation and leaching by direct sunlight.

Limber pines are the tree pioneers of the lava terrain. Their seedlings often find suitable conditions for germination in rock crevices long before surrounding landscapes support tree growth. Most common of all the parkâ€™s trees, limber pine is named for its flexible branches. Many park animals depend on this tree in some fashion for their livelihoods.

Limber pine cones stay green and resinous through their first year of development and then turn brown and woody as their seeds mature in the second year. Cones grow to about 4 inches long.

At Craters of the Moon, crevices are of such importance to plants that botanists differentiate between narrow, shallow, and deep crevices when studying this phenomenon. Narrow crevices will support dwarf goldenweed or hairy goldaster. Shallow crevices support scabland penstemon, fernleaf fleabane, and gland cinquefoil. Deep crevices give rise to syringa, ferns, bush rockspirea, tansybush, Lewis mockorange, and even the limber pine tree. Complete soil cover and then vegetative cover can develop on these lava flows only after crevices have first become filled with soil.

Plants exploit other means of protection to survive in this harsh environment. Shaded and wind-sheltered, the northern side of a cinder cone can support grass, shrubs, and limber pine trees while the coneâ€™s southern face supports only scattered herbs. Most cinder cones in the park show distinct differences of plant cover between their northern and southern exposures. Northern exposures are cooler and more moist than southern exposures, which receive far more direct sunlight. In addition, here at Craters of the Moon, the prevailing southwesterly winds compound the ability of the dry heat to rob porous cinder cone surfaces and their living organisms of precious moisture.

The build-up of successive lava flows has so raised the landscape that it now intercepts wind currents that operate higher above surrounding plains. Limber pine trees find footholds on the shaded and sheltered northern exposures of cinder cones. Bitterbrush and rabbitbrush shrubs that can barely survive on the lower skirts of a cinder coneâ€™s southern side may grow two-thirds of the way up its protected northern face. For many species of plants the limits of habitability on this volcanic landscape are narrowly defined. Very small variations in their situations can determine success or failure.

Travelers often ask park rangers whether or not some of the parkâ€™s plants were planted by people. The plants in question are dwarf buckwheats and grow in cinder gardens. It is their incredibly even spacing that creates an orderliness that is easy to mistake for human design. The regular spacing comes about because of the competition for moisture, however. The root systems of these plants exploit the available water from an area of ground surface much larger than the spread of their foliage. In this way, mature plants can fend off competition by using the moisture that would be required for a potentially encroaching plant to become established. The effect is an even spacing that makes it appear, indeed, as though someone had set out the plants on measured centers.

Craters of the Moon abounds with these surprising plant microhabitats that delight explorers on foot. The bleak lava flows separate these emerging pockets of new life, isolating them like islands or oases within their barren volcanic surroundings.

Scientists have studied Carey Kipuka, an island of plantlife in the most southern part of the park, to find out what changes have occurred in the biologic community.Kipukais a Hawaiian name given to an area of older land that is surrounded by younger lava flows. Recent lava flows did not overrun Carey Kipuka, so its plant cover is unaltered. Shortage of water protected it from livestock grazing that might have changed its character. Its vegetation is a benchmark for comparing plant cover changes on similar sites throughout southern Idaho.

For the National Park Service and other managers of wildlands, kipukasâ€”representing isolated and pristine plant habitat unchanged by human influenceâ€”provide the best answer that we have to the important question, â€œWhat is natural?â€ Armed with a satisfactory answer to that question, it is possible to manage the land ecologically. Park managers can seek to restore natural systems and to allow them to be as self-regulating as possible. It is ironic that Craters of the Moon, a volcanic landscape subjected to profound change, should also protect this informative glimpse of what remains unchanged.

From the parkâ€™s mazes of jumbled rock, ground squirrels fashion homes with many entrances and exits. Opportunistic feeders on vegetable matter, these engaging rodents fall prey to hawks and owls from above and small predatory mammals on the ground. They therefore serve as an important transfer point between plant and animal layers of the parkâ€™s food energy scheme.

In the 1920s, members of the Limbert Expedition, described on pages50and51, followed the flight of doves to locate water as they explored what later became the park.

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Wildflowers carpet Craters of the Moonâ€™s seemingly barren lava fields from early May to late September. The most spectacular shows of wildflowers come with periods of precipitation. In late spring, moisture from snowmeltâ€”supplemented now and then by rainfallâ€”sees the blossoming of most of the delicate annual plants.Many of the parkâ€™s flowering plants, having no mechanisms for conserving moisture, simply complete their life cycles before the middle of summer. This is particularly true of those that grow on the porous cinder gardens into which moisture quickly descends beyond reach of most plantsâ€™ root systems.As summer continues and supplies of moisture slowly dwindle, only the most drought-resistant of flowering plants continue to grow and to bloom. With the onset of autumn rains, only the tiny yellow blossoms of the sagebrush and rabbitbrush remain.Blazing starMonkeyflowerDesert parsleyWild onionBitterrootPaintbrushScabland penstemonArrow-leaved balsamrootScorpionweed

Many of the parkâ€™s flowering plants, having no mechanisms for conserving moisture, simply complete their life cycles before the middle of summer. This is particularly true of those that grow on the porous cinder gardens into which moisture quickly descends beyond reach of most plantsâ€™ root systems.

As summer continues and supplies of moisture slowly dwindle, only the most drought-resistant of flowering plants continue to grow and to bloom. With the onset of autumn rains, only the tiny yellow blossoms of the sagebrush and rabbitbrush remain.

Blazing star

Monkeyflower

Desert parsley

Wild onion

Bitterroot

Paintbrush

Scabland penstemon

Arrow-leaved balsamroot

Scorpionweed

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Brad Griffith could be called the mule deer man. In 1980, this wildlife researcher began a three-year study of the mule deer herd that summers in the park. The immediate concern was that the deer, protected inside the park, might be overpopulating their range and endangering their habitat. Griffith set out to find out just how the deer use the area, what their population level is, and how certain factorsâ€”production, mortality, and distributionâ€”affect their population dynamics. The mule deer use the park April through November only, because winter brings snows too deep for the deer to find food here. The most striking finding of Griffithâ€™s research is that the mule deer at Craters of the Moonâ€”unlike mule deer studied elsewhereâ€”have a dual summer range. Put simply, the mule deer have had to undergo behavior modification to live here. The deer move back into the southern park in mid-April, living in the protected wilderness area there. While in the wilderness area, the parkâ€™s deer routinely live up to nearly 10 miles from open water, getting their water from food, dew, fog, and temporary puddles. This area has higher quality forage for these deer than any other part of their annual range. The trade-off is that the wilderness area has almost no open water. When the moisture content of their forage decreases in summer, usually in July, the deer move up to the northern part of the parkwhere there is open water. Their habits in the northern part of the park are unusual, too, Griffith says, because there the deer live in much closer quarters than other herds are known to tolerate on summer ranges. They live in this wildlife equivalent of an apartment complex until the fall rains come. Then they move back down to the wilderness area. The deer make this unusual summer migration, Griffith suggests, to avail themselves of the high quality forage in the southern park. â€œThe park serves as an island of high quality habitat for mule deer,â€ he wrote in his report. It is now known the deer will leave the wilderness area for the northern park after 12 days with daytime highs above 80Â°F and nighttime lows above 50Â°F in summer. â€œWe canâ€™t really predict this,â€ Park Ranger Neil King says, â€œbut the deer know when this is.â€ What is happening is that the percentage of water in their forage plants falls below what is necessary to sustain the deer with increasingly hot weather. As you would expect, does nursing two fawns leave a couple days earlier than does with only one fawn. The rate at which their fawns survive to the fall of the year is astonishing. â€œThis is an incredibly productive herd,â€ Griffith says, â€œright up there with the highest fawn survival rate of any western mule deer herd.â€ Park rangers continue Griffithâ€™s studies by taking deer census counts.{Map showing fall, summer, and spring migrations}

{Map showing fall, summer, and spring migrations}

The Northern Shoshone regularly passed through the Craters of the Moon area on their annual summer migration from the Snake River to the Camas Prairie, west of the park. They took this journey to get out of the hot desert and into the cooler mountains. There they could gather root crops and hunt marmots, jackrabbits, porcupines, and ground squirrels. As they passed through todayâ€™s park, they left behind arrowheads, choppers, and scrapers and built stone circles that may have been used for ceremonial purposes. These artifacts and structures are evidence the Indians were temporary visitors to this vast volcanic landscape.

Not surprisingly, archeologists have concluded that Indians did not make their homes on this immense lava field. Astronauts would one day trek about Craters of the Moon in hopes that experiencing its harshly alien environment would make walking on the moon less disorienting for them. No wonder people have not chosen to live on these hot, black, sometimes sharp lava flows on which you must line the flight of doves to locate drinking water.

Indians did traverse this area on annual summer migrations, however, as shown by the developed trails and many sites where artifacts of Northern Shoshone culture have been found. Most of these archeological sites are not easily discerned by the untrained eye, but the stone windbreaks at Indian Tunnel are easily examined. Rings of rocks that may have been used for temporary shelter, hunting blinds, or religious purposes, numerous stone tools, and the hammerstones and chippings of arrowhead making are found scattered throughout the lava flows. Some of the harder, dense volcanic materials found here were made into crude cutting and scraping tools and projectile points. Such evidence suggests only short forays into the lavas for hunting or collecting by small groups.

The Northern Shoshone were a hunting and gathering culture directly dependent on what the land offered. They turned what they could of this volcanic environment to their benefit. Before settlement by Europeans, the vicinity of the park boasted several game species that are rare or absent from Craters of the Moon today. These included elk, wolf, bison, grizzly and black bear, and the cougar. Bighorn sheep, whose males sport characteristic headgear of large, curled horns, have been absent from the park since about 1920.

Military explorer U.S. Army Capt. B.L.E. Bonneville left impressions of the Craters of the Moon lava field in his travel diaries in the early 1800s. InThe Adventures of Captain Bonneville, which were basedon the diaries, 19th-century author Washington Irving pictures a place â€œwhere nothing meets the eye but a desolate and awful waste, where no grass grows nor water runs, and where nothing is to be seen but lava.â€ Irving is perhaps most famous forThe Legend of Sleepy Hollow, but hisAdventuresis considered a significant period work about the West and provided this early, if brief, glimpse of a then unnamed Craters of the Moon.

Pioneers working westward in the 19th century sought either gold or affordable farm or ranch lands so they, like the Northern Shoshone, bypassed these lava wastes. Later, nearby settlers would venture into this area in search of additional grazing lands. Finding none, they left Craters of the Moon substantially alone.

Early pioneers who left traces in the vicinity of the park did so by following what eventually came to be known as Goodaleâ€™s Cutoff. The route was based on Indian trails that skirted the lava fields in the northern section of the park. It came into use in the early 1850s as an alternate to the regular route of the Oregon Trail. Shoshone Indian hostilities along the Snake River part of the trailâ€”one such incident is memorialized in Idahoâ€™s Massacre Rocks State Parkâ€”led the emigrants to search for a safer route. They were headed for Oregon, particularly the Walla Walla area around Whitman Mission, family groups in search of agricultural lands for settlement. Emigrants traveling it in 1854 noticed names carved in rocks and trees along its route. It was named in 1862 by travelers apparently grateful to their guide, Tim Goodale, whose presence, they felt, had prevented Indian attacks. Illinois-born Goodale was cut in the mold of the typical early trapper and trader of the Far West. He was known to the famous fur trade brothers Solomon and William Sublette. His name turned up at such fur trade locales as Pueblo, Taos, Fort Bridger, and Fort Laramie over a period of at least 20 years.

After the discovery of gold in Idahoâ€™s Salmon River country, a party of emigrants persuaded Goodale to guide them over the route they would name for him. Goodale was an experienced guide: in 1861, he had served in that capacity for a military survey west of Denver. The large band of emigrants set out in July and was joined by more wagons at Craters of theMoon. Eventually their numbers included 795 men and 300 women and children. Indian attacks occurred frequently along the Oregon Trail at that time, but the size of this group evidently discouraged such incursions. The trip was not without incident, but Goodaleâ€™s reputation remained sufficiently intact for his clients to affix his name to the route. Subsequent modifications and the addition of a ferry crossing on the Snake River made Goodaleâ€™s Cutoff into a popular route for western emigration. Traces of it are still visible in the vicinity of the park today.

Curiosity about this uninhabitable area eventually led to more detailed knowledge of Craters of the Moon and knowledge led to its preservation. Geologists Israel C. Russell and Harold T. Stearns of the U.S. Geological Survey explored here in 1901 and 1923, respectively. Taxidermist-turned-lecturer Robert Limbert explored the area in the early 1920s. Limbert made three trips. On the first two, he more or less retraced the steps of these geologists. On his third and most ambitious trek, Limbert and W. L. Cole traversed what is now the park and the Craters of the Moon Wilderness Area south to north, starting from the nearby community of Minidoka. Their route took them by Two Point Butte, Echo Crater, Big Craters, North Crater Flow and out to the Old Arco-Carey Road, then known as the Yellowstone Park and Lincoln Highway. These explorations and their attendant publicity inNational Geographic Magazinewere instrumental in the proclamation of Craters of the Moon as a national monument by President Calvin Coolidge in 1924.

Since Limbertâ€™s day, astronauts have walked both here and on the moon. Despite our now detailed knowledge of the differences between these two places, the nameâ€”and much of the parkâ€™s awe-inspiring appealâ€”remains the same. It is as though by learning more about both these niches in our universe we somehow have learned more about ourselves as well.

In the mid-1800s the Oregon Trail served as a major route to the West for pioneers. But when hostilities developed along the trail with the Shoshone-Bannock Indians, many of the emigrants began using an alternate route known as Goodaleâ€™s Cutoff. This trail went further north and passed through the present-day park boundary.

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The first known explorations of these lava fields were conducted by two Arco, Idaho, cattlemen in 1879. Arthur Ferris and J.W. Powell were looking for water for their livestock. The first scientific explorations were carried out by Israel C. Russell, surveying the area for the U.S. Geological Survey in 1901 and 1903. Beginning in 1910, Samuel A. Paisely, later to become the parkâ€™s first custodian, also explored these lava fields. In 1921, the U.S.G.S. sent two geologists here, Harold T. Stearns and O.E. Meinzer, with a geologist from the Carnegie Institute. Based on this field work, Stearns recommended that a national monument be created here. Also during the early 20s, the explorations of Idaho entrepreneur Robert W. Limbert caught the publicâ€™s fancy. A report of the explorations of â€œTwo-gunâ€ Bob Limbert was published in the March 1924National Geographic Magazine. Limbert was a Boise, Idaho, taxidermist, tanner, and furrier. He was also an amateur wrestler and quick-draw artist who later performed on the national lecture circuit. Reportedly, Limbert once challenged Al Capone to a pistol duel at 10 paces. Evidently Capone declined. Limbert made three treks into the lava fields between 1921 and 1924. He first explored the more easily accessible northern portion of the lava fields. Limbertâ€™s third expedition crossed the area from south to north, however, starting from Minidoka.The Limbert TrekOn his third expedition, Limbert, Cole, and a dog traversed the lava flows from south to north. The photos that appeared inThe National Geographic Magazinein 1924 were taken on various expeditions.With Limbert were W.L. Cole and an Airedale terrier. Taking the dog along was a mistake, Limbert wrote, â€œfor after three daysâ€™ travel his feet were worn raw and bleeding.â€ Limbert said it was pitiful to watch the dog as it hobbled after them. The landscape was so unusual that Limbert and Cole had difficulty estimating distances. Things would be half again as far away as they had reckoned. In some areas their compass needles went wild with magnetic distortions caused by high concentrations of iron in the lava rock. Bizarre features they foundâ€”such as multi-colored, blow-out cratersâ€”moved Limbert to write: â€œI noticed that at places like these we had almost nothing to say.â€ Limbert and Cole discovered ice caves with ice stalactites. They found water by tracking the flights of mourning doves. They found pockets of cold water (trapped above ground by ice deposits below the surface) covered with yellowjackets fatally numbed by the cold. They drank the water anyway. In desert country, said Limbert, one canâ€™t be too picky. Between Limbertâ€™s lively article in theNational Geographic Magazine, and the reports of geologist Stearns, President Calvin Coolidge was induced to designate part of the lava fields as Craters of the Moon National Monument on May 2, 1924.{untitled}{untitled}

On his third expedition, Limbert, Cole, and a dog traversed the lava flows from south to north. The photos that appeared inThe National Geographic Magazinein 1924 were taken on various expeditions.

With Limbert were W.L. Cole and an Airedale terrier. Taking the dog along was a mistake, Limbert wrote, â€œfor after three daysâ€™ travel his feet were worn raw and bleeding.â€ Limbert said it was pitiful to watch the dog as it hobbled after them. The landscape was so unusual that Limbert and Cole had difficulty estimating distances. Things would be half again as far away as they had reckoned. In some areas their compass needles went wild with magnetic distortions caused by high concentrations of iron in the lava rock. Bizarre features they foundâ€”such as multi-colored, blow-out cratersâ€”moved Limbert to write: â€œI noticed that at places like these we had almost nothing to say.â€ Limbert and Cole discovered ice caves with ice stalactites. They found water by tracking the flights of mourning doves. They found pockets of cold water (trapped above ground by ice deposits below the surface) covered with yellowjackets fatally numbed by the cold. They drank the water anyway. In desert country, said Limbert, one canâ€™t be too picky. Between Limbertâ€™s lively article in theNational Geographic Magazine, and the reports of geologist Stearns, President Calvin Coolidge was induced to designate part of the lava fields as Craters of the Moon National Monument on May 2, 1924.

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Craters of the Moon National Monument is located in south-central Idahoâ€™s Snake River Plain, midway between Boise, Idaho, and Grand Teton and Yellowstone National Parks. The park includes 53,545 acres, and the elevation at the visitor center is 5,900 feet above sea level. U.S. 20-26-93 gives access to the park. Nominal entrance fees are charged. Golden Eagle, Golden Age, and Golden Access passports are honored and may be obtained at the entrance station.

Park facilities are open and naturalist programs are conducted from mid-June through Labor Day. From November to April, the Loop Drive (seemap) is closed by snow and park facilities are limited. In spring and fall, the opening and closing of facilities and the Loop Drive are determined by weather conditions, which vary greatly from year to year. In spring the weather is unpredictable. Strong winds may occur and snow and/or freezing rain are not uncommon. Temperatures range from highs in the 50s to lows in the 20sÂ°F. Summer features warm to hot days and cool nights. Expect afternoon winds. There may be very sporadic afternoon thunderstorms, and temperatures may range from the 40s to the 90s. Fall offers generally fair weather with low precipitation and infrequent winds. Early snowstorms are possible, and snow is certain by late fall. Fall temperatures range from highs in the 60s to lows in the 30s. Winter brings the possibility of severe storms with drifting snow. Highway access is often best described as snow-packed. On bright sunny days temperatures may reach into the 40s, but the range is generally from highs in the 30s to lows around minus 10.

Todayâ€™s park encompasses a small portion of the Great Rift and the greater portion of the Craters of the Moon Lava Field near Arco, Idaho. Blue arrows on this map show the route of the Limbert Expeditions in the 1920s. The detail map appears onpage 58.

The park visitor center, restrooms, and amphitheater are accessible to the disabled.

U.S. 20-26-93 provides access to Craters of the Moon. No public transportation serves the park. Scheduled airlines serve Idaho Falls, Twin Falls, and Hailey, Idaho. Rental cars are generally available at these airports, but advance reservations are advised. It is about a three-hour drive from the park to Grand Teton National Park, and about a four-hour drive to Yellowstone National Park. The official Idaho State Highway Map is available from the Idaho Transportation Department, P.O. Box 7129, Boise, ID 83707, telephone (208) 334-8000. Idahoâ€™s travel office provides information about cultural activities, scenic tours, outfitters and guides, chambers of commerce, hotels, and motels throughout the state. Write or call Idahoâ€™s Travel Promotion Division, 700 West State Street, Boise, ID 83720-2700, telephone (208) 334-2470.

Please stay on roadways and parking pullouts that are provided. If a vehicle goes off the roadway onto cinders, the cinders are compacted and the tracks may remain visible for 10 to 20 years or more.

Information about the Park.Address specific inquiries about the park to theSuperintendent, Craters of the Moon National Monument, P.O. Box 29, Arco, ID 83213, or telephone (208) 527-3257.

Make the visitor center your first stop in the park. Ask at the information desk for schedules of ranger-led walks, talks, and other programs and for advice about camping.

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The park visitor center is located near the only entrance to the park. Here you will find displays and information to help you plan your visit. Slides, postcards, maps, and other publications about the park are displayed for sale. Park Service rangers at the information counter can answer your questions and help you plan your stay in the park.

The displays alert you to wildflowers and wild animals you might expect to see here. Other exhibits describe the parkâ€™s geologic history. A film explains how lava flowed from fissures in the Earth to create the cinder cones, lava flows, and other volcanic features you will see at Craters of the Moon. The film includes actual footage of eruptions of the same type that occurred here some 2,000 years ago. Check at the visitor center for the schedules of conducted walks and campfire programs. You also can get information here about two self-guiding nature trails and the parkâ€™s Loop Drive (seepage 59).

In summer, ranger-guided walks and other programs give visitors an intimate look at various aspects of the park. Program schedules vary; we suggest that you contact the park for current information prior to arrival. Several sites have been designed to make it easy to see the park on your own. The visitor center is a good place to stop and plan your visit. Evening programs may find you wanting a sweater or light jacket to ward off the chill, despite the hot summer days. These programs explore such topics as the parkâ€™s wildlife and its survival, the powers of nature, and this landscapeâ€™s volcanic origins. Some programs are illustrated with slides or movies and take place in the amphitheater.

Explore three representative areas of the park on self-guiding nature trails.Devils Orchard Trailhelps you understand the complex environmental concerns facing Craters of the Moon. A pamphlet available at the trailhead discusses the major impacts visitors, neighbors, and managers have on the fragile lava landscape. Numbered explanations correspond to markers along the trail. You can walk this trail in about 20 minutes.North Crater Flow Trailtakes you through a lava flow that includes rafted blocks (crater wall fragments) and other interesting features characteristic of basaltic lava flows, which are explained by wayside exhibits. This trail goes through one of the most recent lava flows in the park. The shiny lava flows made early explorers think the volcanic eruptions had happened only a few years before. Please stay on trails in this very fragile area. The park was established to provide protection for its unusual landscape features. These require continuing protection and you can help provide it.Caves Trailallows you the opportunity to explore a lava tube. These caves formed when the surface of lava flow cooled and hardened while the interior remained molten and continued to drain. After the lava drained away, a hollow tube remained. A pamphlet at the trailhead provides a map of the cave area and tells you what to expect as you explore these lava tubes on your own. Wayside exhibits point out the most interesting lava formations along the trail. To see only Indian Tunnel, the largest of the lava tubes, will require nearly one hour.

Visitors read a wayside exhibit beneath imposing monoliths. Flows of lava rafted such fragments of broken crater walls into otherwise inexplicable positions.

Craters of the Moon National MonumentHigh-resolution Version

Craters of the Moon National Monument

High-resolution Version

You can see most of the features for which Craters of the Moon is famous by a combined auto and foot tour along the Loop Drive. With several short walks included, you can make the drive in about two hours. Numbered stops are keyed to the map in the park folder.

1. Visitor Center.The 7-mile Loop Drive begins at the visitor center. Most of the drive is one-way. Spur roads and trailheads enable you to explore this lava field even further.

2. North Crater Flow.A short foot trail crosses the North Crater Flow to a group of crater wall fragments transported by lava flows. This is one of the youngest flows here. The triple twist tree and its 1,350 growth rings have in the past helped date the recency of the last flows here. Along this trail you can see fine examples of pahoehoe lava and aa lava flows (seepage 26). Just beyond the North Crater Flow Trail is the North Crater Trail. This short, steep, self-guiding nature trail leads you to the vent overlooking the crater of a cinder cone.

3. Devils Orchard.Devils Orchard is a group of lava fragments that stand like islands in a sea of cinders. This marks the resting place for blocks of material from the walls of North Crater that broke free and were rafted here on lava flows. The short spur road leads to a self-guiding trail through these weird features. You can easily walk the trail in about 20 minutes. An early morning or evening visit may allow you to observe park wildlife. In springtime, the wildflower displays in the cinder gardens are glorious. In June and early July, dwarf blooming monkeyflowers give the ground a magenta cast.

4. Inferno Cone Viewpoint.From the viewpoint atop Inferno Cone, a landscape of volcanic cinder cones spreads before you to the distant mountain ranges beyond. Notice that the cooler, moister northern slopes of the cones bear noticeably more vegetation than the drier southern slopes, which receive the brunt of sunshine. If you take the short, steep walk to the summit of Inferno Cone, you can easily recognize the chain of cinder cones that defines the Great Rift. Perhaps nowhere else in the park is it so easy to visualize how the volcanic activity broke out along this great fissure in the Earth. Towering in the distance above the lava plain is Big Cinder Butte, one of the worldâ€™s largest, purely basaltic, cinder cones.

5. Big Craters and Spatter Cones Area.Spatter cones formed along the Great Rift fissure where clots of pasty lava stuck together when they fell. The materials and forces of these eruptions originated at depths of approximately 40 miles within the Earth. A short, steep walk to the top of Big Craters offers a view of a series of volcanic vents.

6. Trails to Tree Molds and the Wilderness Area.A spur road just beyond Inferno Cone takes you to trails to the Tree Molds Area and the Craters of the Moon Wilderness. Tree molds formed where molten lava flows encased trees and then hardened (seepage 27). The cylindrical molds that remained after the wood burned and rotted away range from a few inches to more than 1 foot in diameter.

7. Cave Area.At this final stop on the Loop Drive, a Â½-mile walk takes you to the lava tubes. Here you can see Dewdrop, Boy Scout, Beauty, and Surprise Caves and the Indian Tunnel. (For how these lava tubes formed, seepage 30.) Carry a flashlight in all caves except Indian Tunnel.

The campground has about 50 sites. These are available on a first-come, first-served basis. Reservations are not accepted. A daily fee for camping is charged. Water and restrooms are provided in the campground, but there are no showers, dump station, or hookups. Wood fires are prohibited in the park, but grills at each campsite may be used for charcoal fires. The campground accommodates both RVs and tents. During the summer, park rangers present evening programs at the campground amphitheater.

Some of the parkâ€™s most intriguing landscapes lie beyond the roadâ€™s end in the 68-square-mile Craters of the Moon Wilderness Area. Only two trails penetrate the wilderness, and these for only short distances. After the three-mile trail to Echo Crater runs out, you are on your own. For further exploration, you can simply follow the Great Rift and its chain of cinder cones. These landmarks help you find your way.

To explore farther afield, you should have a good topographic map and basic map skills. You can purchase such a map at the visitor center. All hikers who plan to stay overnight in the wilderness are required to register with a park ranger. Backcountry use permits are available free at the visitor center.

Each hiker should carry at least one gallon of water for each day out; even more may be necessary during the hot summer. There is no drinking water available in the wilderness. The best times for wilderness travel are May-June and September-October. Daytime temperatures are usually mild then, while nights are cool, but you must be prepared for inclement and very cold weather in these transitional months. Summer daytime temperatures climb into the 90s, and reflected heat off the lavas may be even higher. Long distance hiking is not very pleasant then, and the weight of necessary drinking water is burdensome.

Sturdy boots and long pants are necessary gear for the jagged aa lava flows. Bring clothing for both hot and cool weather; both can occur the same day in this desert climate. (See drinking water warningabove.)

Campfires are prohibited in the backcountry. Carry a self-contained backpack stove and fuel. Mechanized vehicles, including bicycles, are prohibited in the wilderness area. Pets are also prohibited in the wilderness. Pack out everything that you pack inâ€”and any trash you find that others left behind. A good admonition is: â€œTake only pictures, and try not to leave so much as a footprint.â€

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