Craters of the Moon National Monument and Preserve is a United States national monument in the Snake River Plain of Central Idaho. The park was created to protect a vast landscape of lava flows with scattered islands of cinder cones and sagebrush. Starting 15,000 years ago, the landscape was created by molten lava flows. While the park's landscape varies tremendously from the celestial body after which it was named, it was nevertheless visited in 1969 by Apollo 14 astronauts Alan Shepard, Edgar Mitchell, Joe Engle and Eugene Cernan who explored the lava landscape in order to learn the basics of volcanic geology in preparation for future trips to the moon.

Understand

Lava flows

History

The park was created in 1924 by President Calvin Coolidge, who at the time described it as "a weird and scenic landscape peculiar to itself". The area was designated the Craters of the Moon Wilderness in 1970 by Congress, the first such designation within the National Park Service; it was also certified as a Dark Sky Park by DarkSky International.

Landscape

Over the past 15,000 years, lava eruptions created a rugged but scenic landscape that has forced animals and plants to adapt, and people to endure, detour, or ponder. Located on the Snake River Plain, a volcanic terrain spanning southern Idaho, the Monument and Preserve encompasses the Great Rift volcanic rift zone. In places, this plain is 60 miles wide, with basalt lava deposits over 10,000 feet deep in some locations. Eruptions 2,000 years ago at the Craters of the Moon and the Wapi lava fields are among the most recent volcanic activity to take place anywhere in this immense geographic area. Features visible today include an isolated landscape filled with such features as cinder cones, spatter cones, lava tubes, and several types of lava flows.

Flora and fauna

Flora and lava

Despite the seemingly barren landscape the park supports a rich diversity of life including more than 660 types of plants and over 280 animal species. While searing lava flows that initially destroyed everything in their path today protect the last refuges of intact sagebrush steppe communities on the Snake River Plain. These islands of vegetation, known as kipukas, provide important examples of what is "natural".

Animals seen most frequently in the park are birds and some rodents. The changing weather and seasons play a large role in determining which animals are active at any given time. Most desert animals are nocturnal, or mainly active at night, and include woodrats (also called packrats), skunks, foxes, bobcats, mountain lions, bats, nighthawks, owls, and most other small desert rodents. Animals that are most active at dawn and dusk, when temperatures are cooler than mid-day, are called crepuscular. The subdued morning and evening light helps make them less visible to predators, but is bright enough to allow them to locate food. Crepuscular animals in the park include mule deer, coyotes, porcupines, mountain cottontails, jackrabbits, and many songbirds. The park's diurnal animals are those that are most active during the day, and include ground squirrels, marmots, chipmunks, lizards, snakes, hawks, and eagles. Animals that are unique to Craters of the Moon and the surrounding area include subspecies of Great Basin pocket mouse, pika, yellow pine chipmunk, and yellow-bellied marmot are found nowhere else in the world. Lava tube beetles and many other cave animals are found only in the lava tubes of eastern Idaho.

Over 212 species of birds have been sighted on or over the monument and preserve. Many of these are rocky area or shrubland specialists seen in large numbers in only a few other places in the country. Most are found in the areas of the park where water occurs; many small ponds and lakes formed by spring rains and snow melt provide temporary homes for a surprising number of waterbirds, such as ducks, geese, shorebirds, herons, and gulls. Even swans are sighted regularly during the spring migration north to Canada. A few small riparian areas and aspen clumps provide shelter for warblers, vireos, catbirds, orioles, woodpeckers, and more. Small marshes on the northern edge of the lava flow attract blackbirds, wrens, and herons. The park's shrublands supports birds such as Brewer's Sparrows, Sage Sparrows, Sage Thrasher, and Sage Grouse. Limber pine, rocky mountain, and Utah juniper stands growing in cinder gardens and kipuka areas offer habitat to woodpeckers, flycatchers, chickadees, nuthatches, warblers, sparrows, and finches. These patches of trees in the midst of a vast sea of shrublands and barren lava flows are a beacon to many migrating birds, such as warblers, sparrows, and flycatchers, which reside here for brief periods in the spring and fall. The seemingly barren lava flows provide shelter for Mountain Bluebirds, Violet-green Swallows, and Rock Wrens. During the long, cold winters that are characterized by blowing snow and temperatures well below freezing, birds are still found at Craters of the Moon. Ravens, nutcrackers, and chickadees live here all year. Mountain and arctic birds that stay for the winter include Black and Gray Crowned Rosy-finches, Rough-legged Hawks, Northern Shrikes, Snow Buntings, and in some years even Snowy Owls or Gyrfalcons.

Climate

Craters of the Moon National Monument
Climate chart (explanation)
J F M A M J J A S O N D       1.7     29 11       1.5     33 14       1.4     42 22       1.3     54 30       1.6     64 38       1.4     74 45       0.7     84 54       0.7     83 52       0.7     72 42       1.1     58 32       1.4     40 21       2.1     28 11 Average max. and min. temperatures in °F Precipitation+Snow totals in inches    Data from NOAA (1981-2010)
Metric conversion J F M A M J J A S O N D       43     −2 −12       38     1 −10       36     6 −6       33     12 −1       41     18 3       36     23 7       18     29 12       18     28 11       18     22 6       28     14 0       36     4 −6       53     −2 −12 Average max. and min. temperatures in °C Precipitation+Snow totals in mm

Extremes of weather and climate prevail at Craters of the Moon across seasons and elevations. From the foothills of the Pioneer Mountains on the northern end of the monument to the Snake River on the south, weather conditions vary significantly. As elevation decreases from north to south, temperatures increase and precipitation decreases. Average annual precipitation ranges from 16 inches at the monument Visitor Center to just under 10 inches near the Snake River at Minidoka Dam. In February, average snow depth ranges from 26 inches at the north end of the monument to just 2 inches at the south end. Intense summer sun bakes the black lava, generating surface temperatures of 170 °F (77 °C) and air temperatures in the 90s. Drying winds are a daily occurrence, especially in the afternoon, and may reach 15 to 30 miles per hour. In June, July, and August, the average monthly precipitation is less than two inches. Winter transforms Craters of the Moon into a dramatic landscape of rugged black lava and soft white snow. Fall and spring are milder, with unsettled weather. Despite harsh conditions, delicate wildflowers burst to life in May or June against the more monochromatic background of the cinder slopes: pink monkeyflowers, yellow dwarf buckwheats, white bitterroots, and many others. No matter what the season or the weather, the wide open desert sky at Craters of the Moon offers unobstructed views of spectacular cloud formations, sunrises, sunsets, moonscapes, and stars.

Visitor information

• Park website
• 1 Robert Limbert Visitor Center, ☏ +1 208 527-1300. Labor Day-Memorial Day (off-season): Daily 8AM-4:30PM, closed on Federal holidays during off-season; Memorial Day-Labor Day (Summer): Daily - 8AM-6PM. Start your visit here for maps, information, restrooms and the Craters of the Moon Natural History Association bookstore. (updated Jul 2020)

Get in

By car

From Arco, it is about 20 miles (32 km) southwest on US 20/26/93 to the entrance to the monument, about a 30-minute drive. From Carey, it is about 25 miles (40 km) north on US 20/26/93 to the entrance to the monument, about a 35-minute drive.

By air

The closest commercial airport is Idaho Falls Regional Airport (IDA ^IATA) is just northwest of Idaho Falls. It has limited service from Salt Lake City and Minneapolis/Saint Paul on Delta Connection, Denver Airport on United Express, Las Vegas on Allegiant Air, and Boise and Bozeman on Horizon Air. IDA is located 87 miles (140 km) east of the monument, about a 2-hour drive.

The nearest major airport is Boise Airport (BOI ^IATA), 3201 Airport Way, is serviced by several airlines, including United, Delta, Alaska/Horizon and Southwest. BOI is 178 miles (286 km) west of the monument, about a 3½-hour drive.

Fees and permits

Entrances fees are valid for seven days, allowing unlimited re-entry for the week. Fees as of 2020 are:

• $10 - Per Person on bicycle or foot
• $15 - Motorcycle
• $20 - Private Vehicle
• $35 - Craters Annual Pass

There are several passes for groups traveling together in a private vehicle or individuals on foot/bike that provide free entry to Craters of the Moon National Monument and all national parks, as well as some national monuments, national wildlife refuges, and national forests:

• The $80 Annual Pass (valid for twelve months from date of issue) can be purchased by anyone. Military personnel can obtain a free pass by showing a Common Access Card (CAC) or Military ID.
• The $80 Senior Pass (valid for the life of the holder) is available to U.S. citizens or permanent residents age 62 or over. Applicants must provide documentation of citizenship and age. This pass also provides a 50% discount on some park amenities. Seniors can also obtain a $20 annual pass.
• The free Access Pass (valid for the life of the holder) is available to U.S. citizens or permanent residents with permanent disabilities. Applicants must provide documentation of citizenship and permanent disability. This pass also provides a fifty percent discount on some park amenities.
• The free Volunteer Pass is available to individuals who have volunteered 250 or more hours with federal agencies that participate in the Interagency Pass Program.
• The free Annual 4th Grade Pass (valid for September to August of the 4th grade school year) allows entry to the bearer and any accompanying passengers in a private non-commercial vehicle. Registration at the Every Kid Outdoors website is required.

The National Park Service offers free admission to all national parks on five days every year:

• Martin Luther King Jr. Day (third Monday in January); next observance is January 20, 2025
• The first day of National Park Week (third Saturday in April); next observance is April 19, 2025
• The National Park Service Birthday (August 25)
• National Public Lands Day (fourth Saturday in September); next observance is September 28, 2024
• Veterans Day (November 11)

Get around

The Monument and Preserve remains open all year, although winter snows prevent automobile access around the Loop Drive from mid-November through mid-April. During the open period the road remains open at all hours.

The paved, 7-mile Loop Road connects all of the park's major attractions. Most visitors drive from parking lot to parking lot, but the road is relatively flat and ideal for bicycling. All major sites include short- to medium-length trails, two of which are wheelchair-accessible.

Do

The 7-mile-long (11 km) Loop Road passed many of the key locations in the monument, providing access to trailheads leading to a closer look at the landscape. Listed below are some of the stops along the road.

• North Crater Flow. This lava flow is the youngest in the park. A short ¼-mile (0.4-km) trail leads past lava monoliths. A longer 3.5-mile (5.6 km) trail leads to the North Crater, source of this flow. This trail eventually connects to the Spatter cones stop on the driving tour. 
• Devils Orchard. Fragments of rock rise out of a field of black cinder like flowers, giving rise to the name of this area. A ½-mile (0.8-km) accessible trail leads through the bizarre landscape. 
• Inferno Cone. A steep ½-mile (0.8-km) trail leads to the top of this cinder cone which provides a panoramic view of the lava fields, including one of world's largest cinder cones, Big Cinder Butte. 
• Spatter cones. A short accessible trail leads through the spatter cones, miniature vents that create tiny volcanic cones. 
• Tree Molds. This stop is a trailhead for multiple trails. The 2-mile (3-km) Tree Molds Trail leads past imprints of trees in the lava. The 1.8-mile (2.9-km) Broken-Top Trail circles a cinder cone. The longer, 4-mile (6.4-km) Wilderness Trail visits lava trees, upright molds of trees destroyed by lava flow. 
• Caves. A 1.75-mile (3-km) trail leads to lava tube caves. The caves are open to explore with a permit from the visitor center but you will need to bring a light source. 

Buy

• Craters of the Moon Natural History Association Bookstore (in the Visitor Center), ☏ +1 208 527-1360. Labor Day-Memorial Day (off-season): Daily 8AM-4:30PM, closed on Federal holidays during off-season; Memorial Day-Labor Day (Summer): Daily - 8AM-6PM. 

Eat

The only food in the Monument is from vending machines at the Visitors Center. The town of Arco, 30 minutes to the east, is the closest settlement with restaurants and a grocery store.

Drink

The only drinks in the Monument are from vending machines at the visitors' center.

Sleep

Lodging

There is no lodging in the monument. The nearest lodging is in the town of Arco 18 miles outside of the park.

Camping

• 1 Lava Flow Campground (Located on the Loop Road 0.25 miles past the visitor center.). 51 sites. Lava Flow Campground is accessible by automobile from May through November. Facilities: water, restrooms, charcoal grills, picnic tables. No RV hookups or showers. From November through May, water and other services are limited or unavailable. $15 per night (2020 rates). (updated Jul 2020)

• 2 Group Campground. Nestled behind Sunset Cinder Cone about 0.75 miles up a gravel road on the north side of U.S. Highway 20/26/93. Check-in at the Visitor Center in order to gain access to this gated area. Open May through October (closure dates may vary depending upon snow conditions). Facilities: picnic tables, drinking water, fire grate, vault restroom. $30 Group Campground Fee (2020 rates). (updated Jul 2020)

Backcountry

Free permits for backcountry camping are available from the visitor center. Although there are no fixed campsites, most of the few backcountry campers at Craters of the Moon hike in to the Echo Crater area on the Wilderness Trail (leaving from the Tree Molds parking lot). The volcanic crater is large enough to accommodate several tents with reasonable privacy, and is close to several cinder cones, volcanic craters, and tree molds.

Be aware: water is not available in the backcountry and, on sunny days, the black cinder ground will heat up quickly. Due to the hot, dry climate, hikers may consume water more quickly than expected--bring at least 1 gallon (3.5 L) of water per person per day. Some sources suggest 1.5 gallons. Savvy hikers may wish to do most of their travel before noon, especially if carrying heavy packs.

Stay safe

Cave exploration

The lava tube caves of the Monument are fascinating places to explore but can be dangerous. Take the following precautions when exploring the caves.

• Carry at least three light sources per person. There is no natural light in these caves and you do not want to have to feel your way out in the dark because your batteries went dead or your bulb broke.
• Wear sturdy shoes with thick soles. Lava does not always form a smooth surface and thin soled shoes can be punctured.
• Wear a hard helmet. As with the floor, the roof may contain sharp and rough surfaces. Protect your head.
• Let someone know what cave you will be exploring and when you plan to be back. If you don't show, the rescue personnel will know where to start looking for you.

Hydration

The park's black volcanic cinders and rock heat up quickly on sunny days, leading to ground temperatures over 100 degrees. Bring lots of water, and drink it regularly; potable water is not available away from the visitor center and campground.

Go next

• Arco is the nearest town.

Routes through Craters of the Moon National Monument

Boise ← Mountain Home ←	W  E	→ Arco → Idaho Falls
Boise ← Shoshone ←	W  E	→ Arco → Idaho Falls
Twin Falls ← Shoshone ←	S  N	→ Arco → Missoula