"The surface of the moon as seen through a telescope" is how geologist Harold T. Stearns described this area in 1923. Stearns saw a place where "the dark craters and the cold lava [were] nearly destitute of vegetation." Its strangeness stirred local legends, wider public interest, and then a feature story in National Geographic magazine. In 1924, responding to growing public concern. President Calvin Coolidge used the 1906 Antiquities Act to proclaim Craters of the Moon National Monument, preserving "a weird and scenic landscape, peculiar to itself."

Many lava flows exist on Earth's actual moon, but astronauts confirmed that most lunar craters resulted from meteorite impacts, not volcanism. The craters of Craters of the Moon, however, are definitely of volcanic origin. But where is the volcano? These vast volumes of lava issued not from one volcano but from a series of deep fissures—known collectively as the Great Rift—that cross the Snake River Plain. Beginning 15,000 years ago lava welled up from the Great Rift to produce this vast ocean of rock. The most recent eruption occurred a mere 2,000 years ago, and geologists believe that future events are likely.

Comparisons with Active Volcanics Show How Park Features Formed

SPATTER CONES
The Spatter Cones are excellent examples of these miniature volcanoes.

Very fluid flowing lava forms smooth, rope-like pahoehoe lava.

When thicker and more viscous lava emerges, rubble-like, crusty 'a'a lava results.

CINDER CONES
Big globs of lava blown out of cinder cones may harden in flight, forming lava bombs that can take many shapes.

The trail leading beyond the Spatter Cones provides access to the Big Craters cinder cone complex. When lava with high gas content is erupted foamy cinders accumulate near the vent.

LAVA TUBES
Indian Tunnel is a lava tube, a lava flow that hardened on the outside while the lava still flowed within.

FISSURES and RIFTS
Active volcanism in Hawaii shows how molten lava spreads from a fissure. As parts of an erupting fissure become clogged, fountains of lava accumulate to form cinder cones and other features.

KIPUKAS
Young lava flows that surround older flows can form island-like kipukas. The same searing lava flows that destroyed everything in their path today protect some of the last refuges of natural sagebrush steppe vegetation in this region.

Erupting with Life

While seemingly barren, the park's lava fields and arid sagebrush areas sustain a surprising diversity of plant and animal life. The most startling example of this can be seen when annual wildflower blooms peak in mid-June. Delicate annuals bloom beginning in late May as snowmelt and occasional rains provide needed moisture. Summer dryness allows the more drought-resistant plants to grow and bloom through mid-September.

Dwarf buckwheat plants grow with such regular spacing that you might think someone planted them. But the regular spacing occurs because the plants compete for water through their extensive root systems. Many plants here are adapted to resist losing moisture from the heat and wind. Some have small leaves that minimize water loss. Many grow in crevices that give them shade and wind protection and collect precious moisture. Islands of vegetation—called kipukas—that are surrounded by younger lava flows preserve important areas of the sagebrush steppe plant-and-animal community. These provide relatively undisturbed havens for native plants and animals. Kipukas can also show scientists what the native vegetation was like—before livestock grazing and the invasion by non-native plants like cheat grass—and how native plant communities might now be restored.

Life on Lava
Pikas store dry grasses to eat under the snow in winter. Summer heat here would kill them but for the cool havens of cracks, crevices, and openings beneath the lava surface. Hardy limber pines are the first trees to pioneer lava habitat.

Life in the Sagebrush
Kipukas and other sagebrush covered areas are home to sage grouse, famous for their spring mating displays. These birds are missing from one-third of their historic range in southern Idaho because of the loss of habitat.

Exploration and Preservation of Craters of the Moon

For much of this area's early history the lava lands were a mysterious blank spot on maps. But the Northern Shoshone are known to have passed through the area on their annual migration from the Snake River to the Camas Prairie to the west. They left behind well-worn trails and rock structures like windbreaks and mysterious stone circles on top of the lava.

In the 1800s, people searching for gold or farm and ranch lands mostly avoided the lavas. Early traces, some still visible along US 20/26/93, were left by emigrants who followed Goodale's Cutoff of the Oregon Trail. In the 1850s and 1860s pioneers took this alternate route to avoid conflicts that had flared up with the Shoshone along the Oregon Trail's main route.

Craters of the Moon finally became known through sheer curiosity. Federal geologists explored here in 1901 and again in 1923. Also in the 1920s a taxidermist and Idaho promoter, Robert Limbert, made three epic journeys through the lava. His lectures and articles about these lava lands helped to publicize the area and contributed to the establishment of a national monument here in 1924. In 1970 Congress designated much of the national monument as wilderness, one of the first in the National Park System. In 2000 most of the Great Rift and associated lava fields were added to the national monument. In 2002 Congress established the national preserve. Today the National Park Service and Bureau of Land Management, along with the American people, share the responsibility for taking care of this special place.

Archeological evidence and oral traditions both indicate that Shoshone likely witnessed some volcanic eruptions along the Great Rift.

Oregon-bound pioneers followed the Goodale's Cutoff along the northern edge of the lava lands in the mid-1800s. Present-day Idaho was in the Oregon Territory then. In 1863 it became the Idaho Territory and a state in 1890.

Robert Limbert, Idaho taxidermist and parttime explorer, hiked the length of the Great Rift in 1920. His work drew national attention to the fascinating volcanic formations here—and to the need to protect them.

Harold Stearns, a geologist, described this area as the nation's "most recent fissure eruption" (outside of Hawaii) in 1923. He soon became an outspoken advocate for preserving the area as a national monument.

NASA's Apollo Astronauts Alan Shepard, Edgar Mitchell, Eugene Cernan, and Joe Engle learned basic volcanic geology here in 1969 as they prepared for their moon missions.

Backpackers enjoy the challenge and solitude of the Craters of the Moon Wilderness.

Exploring Craters of the Moon by the Loop Road

Accessibility We strive to make our facilities, services, and programs accessible to all. For information go to the visitor center, ask a ranger, call, or check our websites.

The scenic 7-mile loop road provides access to trails that take you over, under, and around the various volcanic features. Trail mileages are one-way distances. Allow a half-hour for the drive itself and more time for stopping at viewpoints and for hiking the trails.

Visitor Center Begin here with films, exhibits, and the schedule of ranger-led walks and evening programs. The Craters of the Moon Natural History Association bookstore is in the visitor center.

North Crater Flow A 0.3-mile trail crosses one of the youngest flows to monoliths, crater fragments rafted here by lava flows. Nearby, a 1.8-mile trail winds through the vent of North Crater and exits at the Spatter Cones/Big Craters parking lot.

Devils Orchard Island-like lava fragments stand in a sea of cinders. Take the spur road and short walk (0.5-mile, accessible) through these weird features. Learn about human impacts on the park and how the park is being protected today.

(click for larger map)

Inferno Cone From atop this cone (a short, steep 0.2-mile walk) you see cinder cones lined up along the Great Rift. Big Cinder Butte, towering above the lava plain to the south, is one of the world's largest basaltic cinder cones.

Spatter Cones and Big Craters Area A short, wheelchair-accessible trail leads to these miniature volcanoes. You can view the spectacular Big Craters by hiking a steep 0.25-mile part of the North Crater trail that branches off to the west.

Trails to Tree Molds, Broken Top, and Wilderness A spur road after stop 5 leads to this trailhead. View the imprint of lava-charred trees along the 1-mile Tree Molds Trail. Broken Top Trail (self-guiding) goes around a cinder cone (1.8 miles). The Wilderness Trail leads to molds of upright trees called lava trees (2 miles) and the wilderness area beyond.

Cave Area See lava tubes—Dewdrop, Boy Scout, Beauty, and Indian Tunnel—via a 0.8-mile trail across the lava. Obtain a permit, carry a flashlight, and wear sturdy, close-toed shoes before entering any cave. Warning: Exploring these natural, wild caves can be dangerous. Stay out of the hazardous sections marked with signs or barriers.

Planning Your Visit

Craters of the Moon visitor center is 18 miles southwest of Arco, ID, on US 20/26/93. The visitor center offers water and restrooms year-round. A campground (first-come, first-served; no reservations accepted) offers water, restrooms, charcoal grills, and picnic tables but no hookups. Wood is scarce; wood fires are prohibited. A separate camping area serves groups of 10-30; visit www.recreation.gov to reserve. The campground and stops 3, 6, and 7 have waterless restrooms. The loop drive, closed November-April, is excellent for skiing and snowshoeing then. For firearms regulations ask a ranger or visit the park website.

Source: NPS Brochure (2017)

Establishment Craters of the Moon National Monument and Preserve — August 21, 2002 Craters of the Moon Wilderness Area — October 23, 1970 Craters of the Moon National Monument — May 2, 1924

For More Information Please Visit The OFFICIAL NPS WEBSITE

A Review of Scientific Research at Craters of the Moon National Monument Station Bulletin 50 of the Forest, Wildlife and Range Experiment Station (Jennifer A. Blakesley and R. Gerald Wright, University of Idaho, February 1988)

A Survey of Bat Use in CRMO Caves Open to the Public After One Year of Closure Due to COVID-19 DRAFT (Todd Stefanic and Mauro Hernandez, May 2021)

A Systematic Survey for Cultural Resources at Craters of the Moon National Monument (Dorothy Sammons and James McLaughlin, 1992)

An Ecological Survey of Mammals of the Craters of the Moon National Monument (Timothy Dee Fuller, 1969)

An Overview of the Yellowstone Hotspot — Topography, Earthquakes and Space-Time Evolution (©Robert B. Smith, 2000)

Archaeological Overview, Craters of the Moon National Monument and Preserve (L. Suzann Henrikson, Kaylon W. McAlister and Montana M. Long, c2006)

Astronauts Visit Craters of the Moon (c1999)

Backcountry/Wilderness Management Plan, Craters of the Moon National Monument (Shelley Sparhawk, 1989)

Bat Hibernacula Surveys in Craters of the Moon National Monument and Preserve: 2012-2013 Status Report NPS Natural Resource Data Series NPS/UCBN/NRDS-2013/519 (Todd Stefanic and Thomas J. Rodhouse, August 2013)

Bat Hibernacula Surveys in Craters of the Moon National Monument and Preserve: 2014 Status Report NPS Natural Resource Data Series NPS/UCBN/NRDS-2015/800 (Todd Stefanic and Thomas J. Rodhouse, May 2015)

Bat Hibernacula Surveys in Craters of the Moon National Monument and Preserve: 2015 Status Report NPS Natural Resource Report NPS/UCBN/NRR-2016/1138 (Kathleen Slocum, Todd Stefanic and Thomas J. Rodhouse, February 2016)

Bat Hibernacula Surveys in Craters of the Moon National Monument and Preserve: 2016 Status Report NPS Natural Resource Report NPS/UCBN/NRR-2016/1333 (Kathleen Slocum,, Arianne Millet, Todd Stefanic and Thomas J. Rodhouse, November 2016)

Bat Hibernacula Surveys in Craters of the Moon National Monument and Preserve: 2017 Status Report NPS Natural Resource Report NPS/UCBN/NRR-2017/1477 (Kathleen Slocum, Todd Stefanic and Thomas J. Rodhouse, July 2017)

Bat Species Presence on Craters of the Moon National Monument and Preserve (Todd Stefanic, November 2021)

Biology of the Idaho Lava Tube Bettle, Glacicavicola (Stewart B. Peck, extract from NSS Bulletin, Vol. 36 No. 1, January 1974; ©The National Speleological Society)

Cave Management Program, Craters of the Moon National Monument (March 1993)

Classification of the Plant Communities of Craters of the Moon National Monument and Preserve, Idaho NPS Natural Resources Technical Report NPS/UCBN/NRTR-2008/096 (Steven K. Rust and Paige Wolken, January 2008)

Craters of the Moon National Monument (Willis A. Eggler, 1936)

Administrative History: Craters of the Moon National Monument (HTML edition) (David Louter, 1992)

Bird Checklist (2002)

Broken Top Loop Trail Concept Plan, Craters of the Moon National Monument, Idaho (2001)

Commonly Seen Plants (Doug Owen, 2002)

Compositional Evolution of Polygenetic Fissure Volcanic Systems: Insights From the Latest Eruptions at Craters of the Moon Volcanic Field (John Chadwick, Claire Chadwick and George Kamenov, extract from Geochemistry, Geophysics, Geosystems, Vol. 24, 2023)

Craters of the Moon Chronology (1998)

Craters of the Moon: Life in a Volcanic Landscape (Vern Crawford, 1978)

Craters of the Moon National Monument, Idaho (HTML edition) Idaho Bureau of Mines and Geology Bulletin No. 13 (Harold T. Stearns, July 1928)

Craters of the Moon National Park (Congressional Record, Vol. 135 No. 164, November 20, 1989)

Draft General Management Plan / Environmental Impact Statement, Craters of the Moon National Monument and Preserve, Idaho (March 2004)

Ecological Characteristics of Mule Deer: Craters of the Moon National Monument, Idaho CPSU/UI B 83-2 (Brad Griffith, 1983)

First Field Investigation Report of Kipuka Addition to Craters of the Moon National Monument Investigation Date - September 3, 1958, Blaine County, Idaho (Adolph Murie, February 1959)

Foundation Document, Craters of the Moon National Monument and Preserve, Idaho (July 2014)

Foundation Document Overview, Craters of the Moon National Monument and Preserve, Idaho (July 2014)

From Wasteland to Wonderland: Craters of the Moon National Monument (David Louter, extract from Idaho Yesterdays, Vol. 40 No. 2, Summer 1996, ©Idaho State Historical Society)

General Management Plan: Craters of the Moon National Monument (June 1992)

Geologic Points of Interest of Broken Top Area (Andrew J. Tveter, Emerald K. Shirley and Douglass E. Owen, 2009)

Geologic Points of Interest in the Echo Crater Area (Steven M. Chemtob and Benjamin R. Brulet, 2006)

Geologic Points of Interest near the Visitor Center Area (Tiffany A. Rivera, Shaina M. Keane and Douglass E. Owen, 2007)

Geologic Resource Evaluation Report, Craters of the Moon National Monument and Preserve NPS Natural Resource Report NPS/NRPC/GRD/NRR-2018/1783 (Katie KellerLynn, October 2018)

Geology of Craters of the Moon (Douglass E. Owen, rev. January 2008)

Geology of Craters of the Moon (Douglass E. Owen and Sonja M. Melander, 2014)

Geo-Ranger, Craters of the Moon National Monument and Preserve (Date Unknown)

Herpetological inventory of Craters of the Moon National Monument 1999-2001 NPS Natural Resources Technical Report NPS/UCBN/NRTR-2010/303 (John R. Lee and Charles R. Peterson, March 2010)

Hiking the Great Rift (J.H. Walz, 1993)

Historic & Contemporary Evidence for Grizzly Bear and Gray Wolf in Craters of the Moon National Monument and Preserve (M. Munts, 2004)

Historic Context Statements: Craters of the Moon National Monument (HTML edition) (David Louter, 1995)

Historical Overview for the Craters of the Moon National Monument of Idaho (Michael Ostrogorsky, 1983)

History of Arco Tunnel and Bats 1853-2017: A Lava Tube Cave on Craters of the Moon National Monument and Preserve (Todd Stefanic, March 10, 2017)

Illustrated Glossary of Volcanic Terms (undated)

Impacts of Visitor Spending on the Local Economy: Craters of the Moon National Monument and Preserve, 2004 (Daniel J. Stynes, June 2006)

Insects of Craters of the Moon National Monument, Idaho University of Idaho Miscellaneous Series No. 8 (Donald S. Horning, Jr. and William F. Barr, May 1970)

Interpreting Biological Diversity at Craters of the Moon National Monument and Preserve NPS Natural Resource Report NPS/UCBN/NRR-2007/019 (Sarah E. Slaton and Levi T. Novey, December 2007)

Interpreting Cultural Resources at Craters of the Moon National Monument & Preserve (Lennie Ramacher, March 2011)

Interview with James Morris, Superintendent 1995-2005 (abridged version) (Lenard Ramacher, March 18, 2013)

Lava Caves of Craters of the Moon National Monument, Arco, Idaho (S. Peck, 1962)

Legislative History for Craters of the Moon National Monument (70th Congress through 96th Congress) (Marilee Cogswell, Cathleen Frank and Linda Rhines, November 1985)

Long-Range Interpretive Plan, Craters of the Moon National Monument and Preserve (March 2007)

Mammal Inventory of Craters of the Moon National Monument and Preserve 2003 NPS Natural Resources Technical Report NPS/UCBN/NRTR-2009/272 (Erica Madison, Thomas J. Rodhouse and Lisa K. Garrett, November 2009)

Management Alternatives and Reconnaissance Survey: Expansion of Craters of the Moon National Monument (August 1990 and March 1989)

Managing Critical Resources at Craters of the Moon National Monument: A Curriculum for High School Students (undated)

Museum Management Plan: City of Rocks National Reserve, Craters of the Moon National Monument and Preserve, Hagerman Fossil Beds National Monument, Minidoka Internment National Monument (Robert Applegate, Kent Bush, Brooke Childrey, H. Dale Durham, Phil Gensler, Kirstie Haertel and Diane Nicholson, 2008)

National Register of Historic Places Nomination Form

Goodale's Cutoff (Merle Wells, February 24, 1972)

Natural Resource Condition Assessment, Craters of the Moon National Monument and Preserve NPS Natural Resource Report NPS/UCBN/NRR-2012/602 (John A. Erixson and Mark V. Corrao, December 2012)

Night Sky Condition Assessment from Minidoka National Historic Site and Craters of the Moon National Monument and Preserve (Jeremy White, September 15, 2021)

Paleomagnetism of Basaltic Lava Flows in Coreholes ICPP 213, ICPP-214, ICPP-215, and USGS 128 Near the Vadose Zone Research Park, Idaho Nuclear Technology and Engineering Center, Idaho National Engineering and Environmental Laboratory, Idaho USGS Open-File Report 2003-48 (Duane E. Champion and Theodore C. Herman, 2003)

Paleontological Resource Inventory and Monitoring, Upper Columbia Basin Network NPS TIC# D-259 (Jason P. Kenworthy, Vincent L. Santucci, Michaleen McNerny and Kathryn Snell, August 2005)

Park Newspaper: Summer 1994 • Summer 1995 • 75th Anniversary Commemorative Newspaper 1999 • Summer 2012 • Summer 2013 • Summer 2014

Pika Monitoring at Crater Lake National Park, Craters of the Moon National Monument and Preserve, Lassen Volcanic National Park, and Lava Beds National Monument: 2010 Annual Monitoring Report (Mackenzie R. Jeffress, Lisa K. Garrett and Thomas J. Rodhouse, December 2010)

Pika Monitoring at Crater Lake National Park, Craters of the Moon National Monument and Preserve, Lassen Volcanic National Park, and Lava Beds National Monument: 2010-2014 Status Report NPS Natural Resource Data Series NPS/UCBN/NRDS-2015/782 (Thomas J. Rodhouse and Matthew Hovland, April 2015)

Pika Survey Report for Craters of the Moon National Monument and Preserve (Mackenzie Shardlow and Thomas J. Rodhouse, November 2007)

Plant Survey at Craters of the Moon National Monument & Preserve (Michael Mancuso, extract from Sage Notes, Vol. 46 No. 3, September 2024)

Pygmy Rabbit Inventory at Craters of the Moon National Monument and Preserve: Final Report NPS Natural Resource Report NPS/NRSS/IMD/NRR-2023/2503 (Cirrus Ecological Solutions, LC, April 2023)

Report on a Backpack Trip to South End of Monument, September 12-15, 1960: Craters of the Moon National Monument (David C. Ochsner, 1960)

Resources Management Plan and Environmental Assessment, Craters of the Moon National Monument (1982)

Robert Limbert (Lennie Ramacher, 2012)

Sagebrush Steppe Vegetation Monitoring in Craters of the Moon National Monument and Preserve: 2019 Annual Report NPS Natural Resource Report NPS/UCBN/NRR-2020/2109 (Melissa M. Nicolli, April 2020)

Sagebrush Steppe Vegetation Monitoring in Craters of the Moon National Monument and Preserve and City of Rocks National Reserve: 2010 Annual Report NPS Natural Resource Technical Report NPS/UCBN/NRTR-2011/462 (Thomas J. Rodhouse, June 2011)

Sagebrush Steppe Vegetation Monitoring in Craters of the Moon National Monument and Preserve, Hagerman Fossil Beds National Monument, John Day Fossil Beds National Monument, and Lake Roosevelt National Recreation Area: 2009 Annual Report NPS Natural Resource Technical Report NPS/UCBN/NRTR-2010/302 (Thomas J. Rodhouse, March 2010)

Scenes and Experiences Among the Volcanic Regions of Central Idaho (R.W. Limbert, 1923)

Short History, Craters of the Moon National Monument (R.C. Zink, 1956)

Soil Survey of Craters of the Moon National Monument and Preserve, Idaho (2010)

State of the Park Report, Craters of the Moon National Monument and Preserve, Idaho State of the Park Series No. 24 (2016)

Statement for Management, Craters of the Moon National Monument (February 1979)

Status of White Pines Across Five Western National Park Units: Initial Assessment of Stand Structure and Condition NPS Natural Resource Report NPS/KLMN/NRR—2021/2232 (Matthew J. Reilly, Jonathan C. B. Nesmith, Sean B. Smith, Devin S. Stucki and Erik S. Jules, February 2021)

Strategic Plan for Craters of the Moon National Monument Fiscal Year 2000-2005 (2001)

Superintendent's Annual Narrative Report: 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004

Survey of Plant Communities of Kipukas within Craters of the Moon National Monument and Preserve Final Report (Nancy Huntly, June 2009)

Teacher's Guide to Craters of the Moon: A Curriculum on Monument Geology, History and Ecology for Grades 5-6 (undated)

The Craters of the Moon National Monument Wildlife Database: Operating Manual Cooperative Park Studies Unit (Roger A. Hoffman, 1988)

The Crystal Ice Caves: History and Development of The Area (undated)

The Geologic Story of Big Craters, Craters of the Moon National Monument (Robert C. Zink, July 16, 1957)

The Great Rift, Idaho: National Registry of Natural Landmarks (1992)

The Sheepeater Indians (Sven Liljeblad, Idaho State Historical Society Reference Series No. 24, April 1962, reissued May 1972)

Thru the "Craters of the Moon," in Idaho (R.W. Limbert, 1923)

Topographic Base Map: Craters of the Moon National Monument (1946)

Treasures of the Craters, Field Project (C.G. Hammer, November 30, 1990)

Unusual Mineralogy of the Crystal Pit Spatter Cone, Craters of the Moon National Monument, Idaho (Stewart B. Peck, extract from NSS Bulletin, Vol. 36 No. 1, January 1974; ©The National Speleological Society)

Upper Columbia Basin Network Aspen Monitoring Report 2007-2017: City of Rocks National Reserve and Craters of the Moon National Monument and Preserve NPS Natural Resource Report NPS/UCBN/NRR-2023/2538 (Eva K. Strand, Stephen C. Bunting, Timothy R. Johnson, Jeff Lonneker and Gordon Discus, July 2023)

Vegetation Mapping Project, Craters of the Moon National Monument and Preserve NPS Natural Resource Technical Report (Paige Wolken, John Apel, Lisa Garrett, Steven Rust, Leona Svancara, John A. Erixson and Thomas M. Richards, November 2006)

Volcanic Geology of Craters of the Moon National Monument (David Clark, 1984)

Volcanic Geology of Craters of the Moon National Monument and Related Areas (David Clark, rev. January 1987)

Wildland Fire Management Plan, Craters of the Moon National Monument, Idaho (October 2000)

Additional Documents can be found at this location

Craters of the Moon National Monument and Preserve