Hiking Underground in a Lava Tube
Lava River Trail, Coconino National Forest, Flagstaff Arizona
Discovered by lumbermen in 1915, Lava River Cave is located about 14 miles northwest of Flagstaff on Highway 180 in the Coconino National Forest. While not the easiest trail to find, it is well worth the effort.
Formed as many as 700,000 years ago, Lava River Cave, also know as Government Cave, is really a lava tube. Part of the San Francisco Volcanic field, it is the longest lava tube in Arizona.
While the thought of hiking in a cave can sound a little intimidating, you can see from the picture above, it is appropriate even for small children. Care and patience, sturdy footwear, a jacket and several sources of light and everyone will do fine.
In May, 1991, the graffiti was cleaned from the cave and all of the litter removed.
What is a Lava Tube?
Lava tubes form when the outer surface of a molten stream of lava cools and solidifies creating a crust. The inner core remains molten and continues to flow leaving behind a cavity, the lava tube.
As the lava flows out features such as lavacicles and splashdowns (rocks that appear frozen in the floor) can form. In a picture below, you can see ripples in the floor of Lava River Cave from the previously molten lava.
Lava River Cave Entrance
It is a flat, 1/4 of a mile or so hike from the parking lot to the entrance of the lava tube. A sign outside the entrance maps the cave and describes some of the features you'll find in it.
The lava tube is 3/4 to 1 mile long and the ceiling can be as high as 30 ft. The cave drops about 100 feet in elevation from the opening to the end.
The opening to the cave looks like it is in a massive boulder rock garden. After crouching down to enter the cave and scrambling down several (possibly 15- 20 feet or more) we reached the floor. At the floor we could stand without a problem. Caution: Once you get away from the opening, you are in total darkness.
At no point in the hike did we feel cramped, crowded or claustrophobic. It was similar to walking in a large train tunnel. In fact, a family with small children used patience and coaxing to get the kids down from the opening. Once they were in, they all did fine.
If you go, plan appropriately. In addition to water, wear a jacket. It is cool in the lava tube. The temperatures inside are usually 35-45°F, but can be as low as 32°F at the opening. Ice may form there. While the cave was dry, moisture may be found on the walls, floor, and ceiling.
Wear good closed-toe shoes and consider gloves because you will be grabbing onto rocks. The walls, floor and ceiling are rough.
It will be dark in there. Bring a flash light with fresh batteries. Ideally, bring at least 1 or 2 for each hiker and a spare or 2.
After scrambling down the rocks to get to the floor of the cave, it was basically a flat walk. There were some smaller rocks in the floor as well as a few larger ones that we had to climb over or around.
Approximately 1/3 to 1/2 way into the cave, the path splits. According to other hikers, if you follow the trail to the right, you may have to crawl before you get to the end. Follow the trail to the left and the ceiling can reach a height of up to 30 ft.
Because of time constraints, we turned around at the point the cave divided. All told, we were in the cave less than 45 minutes. I would think you could make it to the end and back, particularly if you took the left fork, in less than 90 minutes.
Small animals, such as squirrels, and bats can live in the cave. We did not see any and most hikers rarely do.
How to Get to Lava River Cave, Coconino National Forest
9 Miles north of Flagstaff on Route 180 turn left (west) on to FR 245 (milepost 230). In 3 miles turn left on to FR 171 (there is a sign). 1 mile on FR 171, turn left on to FR 171B. The parking lot is about 1/4 mile on FR 171B
Be aware that FR 245, FR 171, and FR 171B are dirt roads. Access may be limited in the winter months.
GPS: N35° 20' 32.1714", W-111° 50' 8.196"
Other Lava Tubes
Lava River Cave is not the only lava tube in the world, the U.S., or for that matter, even in Arizona. There is another lava tube at Sunset Crater Volcano National Monument on the other side of the San Francisco Peaks. This tube is closed to the public because it is starting to collapse.
Thurston Lava Tube, Big Island, Hawai'i
Thurston Lava Tube, Volcanoes National Park, Big Island Hawai'i
As you can see from the pictures, Thurston Lava Tube is far more tourist friendly than Lava River Cave. Thurston Lava Tube, or Nahuku, has walkways, steps, and most importantly, lights.
Other Lava Tubes in the United States:
- Lava Beds National Monument, northeastern California, the largest concentration of lava tubes in the U.S.
- Kazumura Cave, Big Island, Hawaii, most extensive and greatest linear extent (40.7 miles) of any lava tube in the world.
- Lava River Cave, Newberry National Volcanic Monument, Bend, Oregon
- Ape Cave, Gifford Pinchot National Forest, south of Mount St. Helens, Washington, longest contiguous lava tube in the continental U.S.
Lava Tubes Around the World:
- Canary Islands
There are even lava tubes on the moon.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
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© 2012 bankscottage