By Tetona Dunlap Twin Falls Times-News
ARCO, Idaho — In only a few places in the United States can you walk over what was once lava and explore an underground lava tube crafted by molten rock.
Instead of flying more than five hours to Hawaii, drive less than two hours north of Twin Falls, Idaho, to Craters of the Moon National Monument and Preserve near Arco.
Here you’ll find an otherworldly landscape, an example of what the ground beneath your feet is capable of producing.
Although no bright orange lava flows here now, the gnarled and crusty terrain frozen in time traces the tale of rivers of lava that gushed from fissures across the Snake River Plain called the Great Rift.
In 1923 geologist Harold Stearns described Craters of the Moon as the nation’s most recent fissure eruption outside of Hawaii. The most recent eruption at Craters was just 2,000 years ago.
If you can’t spend half the day exploring all that the monument and preserve has to offer, there are two things you must see, said Lennie Ramacher, interpretive park ranger and volunteer coordinator: the spatter cones and the caves.
The spatter cones are especially interesting, he said, because they are formed during the final gasps of an eruption as lava plops out in gigantic globs.
You can take the short but steep walk up to the top of one of these cones. There is also a handicapped-accessible trail that is easier to climb to the top of Snow Cone, which is about 300 feet deep and always has snow in the bottom.
A lava tube is an underground tunnel that forms when the surface of flowing lava cools faster than the lava beneath. Later, when part of a tube collapses, it creates an opening to the natural cave.
One of the more popular lava tubes to explore is Indian Tunnel, the perfect cave for families with young children who want to venture below ground together but don’t want to walk through complete darkness.
You can reach Indian Tunnel and three other caves — Dewdrop, Boy Scout and Beauty — by way of a half-mile paved trail across a field of lava. Boy Scout is harder than Indian Tunnel to hike through.
Every day a ranger leads guided cave walks; Meet at the caves area trailhead at 9 a.m. Fridays through Sundays, and at 1 p.m. and 4 p.m. daily.
In four of the caves (not Indian Tunnel), you must carry flashlights with extra batteries. Ramacher also suggests bringing a light jacket and water.
Wear tennis shoes or hiking boots because you can feel the jagged ground poking into your shoe soles. Listen quietly to hear the tiny squeaks of bats in the crevices above you.
Before you venture into any of the caves at Craters of Moon you must get a cave permit, required before entering any cave on National Park Service lands.
This helps prevent the spread of white-nose syndrome, a fungal disease that has killed more than 5 million bats in the U.S. since 2005.
Get your permit at the entrance station, the visitor center or on ranger-guided walks.
You will be asked questions: Have you visited a cave or mine since 2005? Do you have any items with you (such as clothing, shoes, flashlights, cameras, watches or phones) that entered the caves or mines you previously visited?
“The bats have no natural defense,” Ramacher said.
At Craters of the Moon you may see pronghorns, mule deer, foxes, coyotes, chipmunks, squirrels and some rattlesnakes.
The lava flows are home to a cute little creature called a pika that resembles a mouse with huge ears but is actually related to a rabbit. Listen for their trademark “Eeep” call and look inside rock crevices for piles of hay and flowers they like to collect.
The Devil’s Orchard is a half-mile trail with trees growing from some of the oldest lava in Craters.
“It’s a peaceful little nature walk,” Ramacher said.
This trail is handicapped accessible, Pets are not allowed on the trails or in the caves.
Other hikes include the 3.5-mile North Crater Trail, the 2-mile Tree Molds Trail and a 7-mile Loop Road connecting all the attractions at Craters. Be sure to visit the visitor center to pick up a monument map.
More adventurous hikers can explore the Craters of the Moon Wilderness Trail and do some backcountry camping, free with a permit.
There are also 51 developed campsites in Lava Flow Campground across from the visitor center. The cost to camp is $10.
There are no RV hookups, but there are flush toilets, water, barbecue pits and picnic tables, and the campground is handicapped accessible.
Campsites are filled first come, first served.
Rangers also conduct nightly programs, junior ranger talks and hikes, and, starting in early August, nighttime hikes.
Hours: During summer, the visitor center is open from 8 a.m. to 6 p.m. daily. The monument is open daily year-round, except for federal holidays during the winter.
Cost: $8 a vehicle. After-hours there is a self-pay post near the entrance kiosk.
Get there: From the intersection of U.S. 20 and U.S. 93, head east on U.S. 20 and go 25 miles past the town of Carey to Craters of the Moon’s entrance.