Tag Archives: geology

List

Top 10 Caves in National Forests

August 12, 2026 Raven About The Parks 2 Comments

The underground world is fun to explore, especially when you get to bring your own flashlights and go at your own pace. That is the only option in most National Forests, with a few notable exceptions for guided tours found on this list. It was the opposite case when I ranked the Top 10 Caves in National Parks back in 2019 (click here to see all our Top 10 Lists).

If you or someone you love are interested in visiting the 155 National Forests, our travel guidebook Out in the Woods makes a great gift!

10. Subway Cave in Lassen National Forest (California)

There are interpretive signs inside this lava tube, including one explaining lavacicles

9. Fulford Cave in White River National Forest (Colorado)

This one and Spring Cave are only accessible April 16 through August 14 and require registration

8. Lava River Cave in Coconino National Forest (Arizona)

This is the first lava tube I ever explored while I was a college student in Flagstaff

7. Mammoth Cave in Dixie National Forest (Utah)

Ice Cave is another option to visit in southwest Utah

6. El Capitan Pit in Tongass National Forest (Alaska)

Prince of Wales Island is mostly karst and includes this deepest pit in the U.S., plus Sophia’s Sinking Stream Cave and Meow Cave

5. Cave of Bells in Coronado National Forest (Arizona)

This cave has a lock on its entry gate, as does Onyx Cave, but are accessible with permission

4. Boyden Cavern in Sequoia National Forest (California)

Guided tours are offered in this show cave outside Kings Canyon National Park

3. Ape Cave in Gifford Pinchot National Forest (Washington)

Timed-entry permits ($2 per vehicle) are required to explore this long lava tube in Mt. St. Helens National Volcanic Monument, but not for Guler Ice Caves

2. Blanchard Springs Caverns in Ozark National Forest (Arkansas)

Limestone springs and caves are all over this region, including this show cave with guided tours

…and finally the #1 cave in a National Forest:

1. Minnetonka Cave in Caribou National Forest (Idaho)

Tickets for a guided tour are required to drive up the narrow road to the parking lot, plus check out nearby Paris Ice Cave

Honorable Mentions

Jot Dean Ice Cave in Shasta National Forest (California)

I stumbled upon this one while visiting Sáttítla Highlands National Monument, also home to lava tubes in Giant Crater

Resurgence Cave in Daniel Boone National Forest (Kentucky)

All caves around here are currently closed to protect bats, including the ones behind Moonshiners Arch

Wind Cave in Cache National Forest (Utah)

Not very dark on this cliffside, but it is a great spot for photographs

Wave Cave in Tonto National Forest (Arizona)

Another one that is more of an amphitheater than a cave, but famous for photos riding the wave

Darby Canyon Wind Cave in Targhee National Forest (Wyoming)

I had not heard of this cave just west of Grand Teton National Park

Sandia Cave in Cibola National Forest (New Mexico)

Located near Albuquerque, it features a unique metal spiral staircase to the entrance

Know someone who loves the National Forests? Gift them our travel guidebook Out in the Woods so they can learn more about all 155 National Forests.

Washington

Mt. Baker National Recreation Area

July 22, 2026 Raven About The Parks Leave a comment

Mt. Baker National Recreation Area

Washington

Managed by U.S. Forest Service, Pacific Northwest Region

Established 1984

8,473 acres

Website: https://www.fs.usda.gov/r06/mbs/recreation/mt-baker-national-recreation-area

Overview

Part of Mt. Baker-Snoqualmie National Forest, Mt. Baker National Recreation Area was set aside to provide a place for snowmobile use on the 10,781-foot volcano’s south slope. Snowmobiling is restricted to certain areas outside the designated Wilderness and requires a minimum snow depth of two feet. Mt. Baker is an active stratovolcano that last had a major eruption 6,700 years ago, but experienced hydro-thermal explosions in 1840 and 1880 that led to dangerous lahars.

Highlights

Park Butte Lookout, Railroad Grade Trail, Scott Paul Trail, Pacific Northwest National Scenic Trail

Must-Do Activity

North of Baker Lake, Park Butte Trailhead is the main access point for Mt. Baker National Recreation Area and has a large parking lot with vault toilets and trash cans. Park Butte Trail immediately enters groves of large western hemlock and Alaska yellow-cedar trees. Taking the split to the right for the Scott Paul Trail creates a 7.5-mile loop, which remains heavily snow covered into mid-June. In addition to snowmobiling, other activities include snowshoeing, skiing, picking huckleberries, and climbing to the summit of Mt. Baker on the Coleman Glacier and Easton Glacier routes. Horseback riding is allowed on Bell Pass, Elbow Lake, Park Butte, and Ridley Creek Trails.

Best Trail

Railroad Grade Trail splits off Park Butte Trail and quickly climbs up to a lateral glacial moraine that offers incredible views of Mt. Baker on clear days. It is used by mountain climbers making their way to the summit of the volcano.

Photographic Opportunity

It is 7.9 miles out-and-back with 2,093 feet of cumulative elevation gain to the Park Butte Lookout, a historic structure built in 1932 that is maintained by Skagit Alpine Club volunteers. It is technically just inside the boundary for Mt. Baker Wilderness.

Peak Season

Summer

Fees

$5 day use (or America the Beautiful pass) at Park Butte Trailhead from May 1 through October 31, and a Washington State Sno-Park permit required the rest of the year.

Road Conditions

Park Butte Trailhead is accessed by taking the pothole-riddled Forest Service Roads 12 and 13 uphill for 8.9 miles. Access to Elbow Lake Trailhead and Ridley Creek Trailhead also require long dirt road drives.

Camping

There are a couple designated free hiker campsites at Park Butte Trailhead with limited options for dispersed car camping situated along the road up to it. Backpacking is popular in this area, especially inside the historic 1932 Park Butte Lookout, which is available on a first-come, first-served basis. There are flat tent pads built at Cathedral Camp, High Camp, Railroad Camp, and Mazama Park Horse Camp in the backcountry.

Ebey’s Landing National Historic Reserve (Washington)

Okanogan National Forest (Washington)

Mt. Baker National Forest (Washington)

Nearest National Park

North Cascades

Explore More – Mt. Baker has the second-most thermally active crater in the Cascade Range, ranking only after which volcano?

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West Virginia

Monongahela National Forest

May 6, 2026 Raven About The Parks Leave a comment

Monongahela National Forest

West Virginia

Managed by U.S. Forest Service, Northern Region

1,706,898 acres (921,150 federal/ 785,748 other)

Website: https://www.fs.usda.gov/r09/monongahela

Overview

Monongahela National Forest contains the highest point in West Virginia, 4,863-foot-tall Spruce Knob with an observation tower for seeing over the trees at its summit. It is part of Spruce Knob-Seneca Rocks National Recreation Area (see our full blog post), which is very popular with rock climbers. The National Forest’s initial 7,200 acres were purchased by the federal government in 1915, and it the grew to 150,367 acres over the next decade. During World War II, the U.S. Army utilized the area as an artillery and mortar range, in addition to training soldiers in climbing techniques at Seneca, Nelson, and Champe Rocks. This area receives an average of 60 inches of annual precipitation on the west side of the Allegheny Front and only half that on the rain shadow side. It is the headwaters of six major rivers: the Monongahela, Potomac, Greenbrier, Elk, Tygart, and Gauley.

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Highlights

Spruce Knob-Seneca Rocks National Recreation Area, Cranberry Glades Botanical Area, Highland Scenic Highway, Lake Sherwood Recreation Area, Gaudineer Knob Scenic Area, Cassell Cave, Sinks of Gandy, Stuart Memorial Drive, Champe Rocks, Dolly Sods Scenic Area

Must-Do Activity

There are 94,991 acres in eight designated Wildernesses in Monongahela National Forest, more than half of which is in the Cranberry Wilderness. A boardwalk traverses the bogs at Cranberry Glades Botanical Area, which has a visitor center run by the Forest Service. Fishing is a popular pastime, especially at Lake Sherwood, Spruce Knob Lake, and Lake Buffalo. When winter conditions are right, there is a snowmobile area on Highland Scenic Highway. The forest is mostly second growth, but 318 acres of old-growth remains, which can be seen at Fanny Bennett Hemlock Grove, Gaudineer Scenic Area (for red spruce), Shavers Mountain Spruce-Hemlock Stand, North Fork Mountain Red Pine Botanical Area, North Spruce Mountain Old Growth Site, and Virgin White Pine Botanical Area.

Best Trail

There is great hiking in Spruce Knob-Seneca Rocks National Recreation Area, and other trails can be found at Lake Sherwood Recreation Area, Falls of Hill Creek Scenic Area, Mt. Porte Canyon, and Stuart Recreation Area. The 17,371-acreDolly Sods Wilderness encompasses much of the Red Creek drainage with high-elevation bogs and heaths like those found in southern Canada.

Watchable Wildlife

It is hard to believe given their abundant numbers today, but in the 1930s white-tailed deer had to be reintroduced from Michigan. In 1969, 23 fishers were reintroduced from New Hampshire. Other large mammals include black bear, red and gray fox, coyote, bobcat, snowshoe hare, beaver, river otter, raccoon, mink, skunk, and opossum. Of the 230 bird species identified, 159 are known to breed here. Approximately 90% of the trout waters in West Virginia are within the National Forest, and trout are stocked at Spruce Knob Lake and other locations.

Photographic Opportunity

The iconic Seneca Rocks are a 900-foot-tall quartzite crag heavily used by rock climbers. On October 22, 1987, a prominent pinnacle dubbed “the Gendarme” fell to the ground.

Peak Season

Summer

Fees

A day use fee applies at Lake Sherwood Recreation Area.

Road Conditions

Most roads are open year-round, including the paved road to the top of Spruce Knob when it is snow-free.

Camping

The National Forest has 23 campgrounds, including popular options in Spruce Knob-Seneca Rocks National Recreation Area at Seneca Shadows and Big Bend (with hot showers).

Wilderness Areas

Big Draft Wilderness

Cranberry Wilderness

Dolly Sods Wilderness

Laurel Fork North Wilderness

Laurel Fork South Wilderness

Otter Creek Wilderness

Roaring Plains West Wilderness

Spice Run Wilderness

Related Sites

Allegheny National Forest (Pennsylvania)

George Washington National Forest (Virginia-West Virginia)

Jefferson National Forest (Virginia-West Virginia-Kentucky)

Harpers Ferry National Historical Park (West Virginia-Virginia-Maryland)

Nearest National Park

New River Gorge

Conifer Tree Species

eastern hemlock, balsam fir, red spruce, red pine, eastern white pine

Flowering Tree Species

black ash, mountain ash, black cherry, yellow birch, sugar maple, red maple, sweet birch, cucumber magnolia, American beech, basswood, speckled alder, mountain laurel, white rhododendron

Explore More – The Monongahela River gets its name from the Lenape language, and it translates as what in English?

Learn more about this and the 154 other National Forests in our new guidebook Out in the Woods

California

Sáttítla Highlands National Monument

April 22, 2026 Raven About The Parks Leave a comment

Sáttítla Highlands National Monument

California

Managed by U.S. Forest Service, Pacific Southwest Region

Established 2025

224,676 acres

Website: https://www.fs.usda.gov/visit/national-monuments/sattitla-highlands-national-monument

Overview

In the northeast corner of California is the largest shield volcano in North America: 7,921-foot Medicine Lake Volcano. Sáttítla Highlands National Monument is spread across Klamath, Shasta, and Modoc National Forests just south of Lava Beds National Monument and features numerous cinder cones and lava fields. Part of the Volcanic Legacy Scenic Byway loops around Medicine Lake, which the Modoc people view as a place of healing. The Pit River Tribe opposed development of geothermal energy sources in this area, spearheading its protection. In the 1960s, NASA astronauts trained at Pumice Crater, four of whom eventually landed on the moon. Sáttítla Highlands National Monument is also important for biodiversity, providing habitat for wildlife species like the Cascades frog, long-toed salamander, and gray-headed pika, as well as numerous fungi, the parasitic sugarstick plant, and Pacific fuzzwort (a rare liverwort).

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Highlights

Medicine Lake Recreation Area, Giant Crater lava tube, Glass Mountain, Black Lava Butte, Fourmile Hill Tree Molds Geologic Area

Must-Do Activity

Most of the developed recreation opportunities surround Medicine Lake, which offers boat ramps, trails, and campgrounds. Giant Crater has the longest known lava tube system in the world at 18 miles, although it is partially collapsed. This Geologic Special Interest Area can be accessed two miles off Medicine Lake Road on Forest Road 43N11. Another unpaved road leads up Glass Mountain, which has a crater full of sharp pieces of rhyolite obsidian and glossy dacite. This remote corner of California has some of the darkest skies in the continental U.S., so it is great for stargazing on moonless nights. In the winter, snowmobiling and cross-country skiing are popular activities on groomed trails.

Best Trail

There is a 4.4-mile loop around Medicine Lake, as well as the one-mile out-and-back Medicine Lake Glass Flow Trail that gains 68 feet of elevation on the north shore. For a more challenging route, Little Mt. Hoffman Trail gains 666 feet over three miles to the fire lookout, which can be rented overnight. Summitting the actual Mt. Hoffman is over 13 miles roundtrip with a 2,000-foot cumulative climb.

Photographic Opportunity

Sáttítla literally translates as “obsidian place” and the volcanic glass prevalent at Glass Mountain has provided humans sharp blades for at least 5,000 years.

Peak Season

Summer

Fees

$5 per vehicle (or the America the Beautiful Pass) at Medicine Lake

Road Conditions

Camping

There are multiple Forest Service campgrounds on Medicine Lake, plus two nearby at Blanche Lake and Bullseye Lake. Dirt roads in Modoc, Shasta, and Klamath National Forests have ample dispersed camping opportunities.

Related Sites

Lava Beds National Monument (California)

Tule Lake National Monument (California)

Lassen National Forest (California)

Berryessa Snow Mountain National Monument (California)

Nearest National Park

Lassen Volcanic

Explore More – Sáttítla translates as “obsidian place” from which indigenous language?

Learn more about the other 137 National Monuments in our book Monumental America: Your Guide to All 138 National Monuments

California

Modoc National Forest

April 15, 2026 Raven About The Parks 10 Comments

Modoc National Forest

California

Managed by U.S. Forest Service, Pacific Southwest Region

1,979,327 acres (1,663,401 federal/ 315,926 other)

Website: https://www.fs.usda.gov/r05/modoc

Overview

In the northeast corner of California, Modoc National Forest contains the largest shield volcano in North America: 7,921-foot Medicine Lake Volcano. This region has a long history of volcanism, as seen at Pumice Stone Mountain, Burnt Lava Flow, High Hole Crater, Hot Spot, and Glass Mountain (composed of rhyolite obsidian and glossy dacite). The basalt-topped plateau of Devil’s Garden is home to an 800-acre stand of western juniper. East of Goose Lake, the Warner Mountains rise from 4,300 feet to 9,892-foot Eagle Peak, and are covered by a mixed conifer forest of lodgepole pine, whitebark pine, ponderosa pine, incense-cedar, and red fir.

Know someone who loves the National Forests? Gift them our travel guidebook Out in the Woods so they can learn more about all 155 National Forests.

Highlights

Sáttítla Highlands National Monument, Volcanic Legacy Scenic Byway, Medicine Lake Recreation Area, Glass Mountain, Devil’s Garden Natural Area, Mill Creek Falls, Highgrade National Recreation Trail, Pine Creek Trail

Must-Do Activity

Medicine Lake offers boat ramps, trails, and campgrounds and nearby is Giant Crater, which has the longest known lava tube system in the world at 18 miles (although it is partially collapsed). Located up a dirt road often blocked by snowdrifts late into the summer, Glass Mountain has a crater full of sharp pieces of rhyolite obsidian and glossy dacite. This remote corner of California has some of the darkest skies in the continental U.S., so it is great for stargazing on moonless nights. In the winter, snowmobiling and cross-country skiing are popular activities on groomed trails. The South Warner Mountain Wilderness is traversed by the 21-mile Summit Trail that passes Eagle Peak, the Devil’s Knob, and The Slide. Mill Creek Falls is also in the Warner Mountains, accessed by a 3.4-mile out-and-back trail.

Best Trail

In the Warner Mountains near the border with Oregon’s Fremont National Forest, the 5.5-mile one-way Highgrade National Recreation Trail provides excellent views of Goose Lake. The trailhead is reached by taking paved County Road 9 five miles east from Highway 395 then turning north on the steep and unpaved Del Pratt Spring Road (Forest Road 47N72) for 6.3 miles. The trail quickly leaves the shade of the forest as it steadily climbs 800 feet through a slope covered in woolly mule’s ears flowers to a saddle west of 8,224-foot Mt. Vida. It is possible to summit Mt. Vida from this point, but the trail heads away toward Yellow Mountain following Forest Road 48N10.

Watchable Wildlife

Modoc National Forest borders Lower Klamath National Wildlife Refuge, in addition to Tule Lake, Clear Lake, and Modoc National Wildlife Refuges. These wetlands provide habitat crucial for bird nesting and migration on the Pacific Flyway. The many lava tubes provide habitat for numerous species of bats, in addition to violet-green swallows and bushy-tailed woodrats. Larger mammals include mule deer, pronghorn, badger, skunk, raccoon, pika, jackrabbit, yellow-bellied marmot, coyote, bobcat, and mountain lion. Large birds found here are great horned owl, short-eared owl, and bald eagle (winter resident). Reptiles are abundant, including the western fence lizard, northern sagebrush lizard, western skink, Rocky Mountain rubber boa, gopher snake, desert night, and western rattlesnake.

Photographic Opportunity

Not far up the steep Highgrade National Recreation Trail there are excellent views of Goose Lake to the west.

Peak Season

Summer

Fees

$5 per vehicle (or the America the Beautiful Pass) at Medicine Lake

Road Conditions

This area receives abundant winter snowfall, and roads can be blocked by snow into July, which we experienced trying to get to Glass Mountain. The road to Medicine Lake is paved, but almost every other road through the National Monument is unpaved, some requiring a high-clearance vehicle. Giant Crater is a Geologic Special Interest Area that can be accessed two miles off Medicine Lake Road on Forest Road 43N11.

Camping

There are multiple Forest Service campgrounds on Medicine Lake, plus two nearby at Blanche Lake and Bullseye Lake. Dirt roads in Modoc National Forest provide ample dispersed campsites.

Wilderness Areas

South Warner Wilderness

Related Sites

Lava Beds National Monument (California)

Tule Lake National Monument (California)

Sáttítla Highlands National Monument (California)

Butte Valley National Grassland (California)

Nearest National Park

Lassen Volcanic