Backway to Lava River Cave
Forest route to Arizona's longest lava tube
This backcountry route approaches Lava River Cave through the volcanic badlands north of Flagstaff, following Forest Service roads through ponderosa pine and aspen groves that few tourists ever see. The cave itself formed 700,000 years ago when molten lava created a mile-long underground tube, now accessible to explorers willing to crawl through pitch-black passages with flashlights and warm clothes. Hart Prairie Road (FR 245) connects to lesser-known FR 171 and FR 171B, winding past ancient cinder cones and lava flows that tell the story of the San Francisco Volcanic Field’s explosive past.
High-clearance vehicles handle the maintained forest roads easily, though winter snow can close access from December through March. The cave maintains a constant 35-40°F temperature year-round, so pack layers and multiple light sources for the underground portion. No permits required for cave access, but bring sturdy shoes and gloves for the rocky scrambling inside. Dispersed camping is allowed throughout the forest, making this an excellent base camp for exploring other volcanic features like Sunset Crater. This route combines accessible forest driving with genuine underground adventure in one of Arizona’s most unique geological features.
Trail Specs
| Difficulty | Easy |
|---|---|
| Trail Type | Scenic Drive |
| Surface | Dirt, Gravel |
| Features | Camping, High Altitude, Scenic |
| Length (miles) | 8 mi / 12.9 km |
| Duration | Half day |
| Max elevation (ft) | 7200 ft |
| Best season | April-November |
| Minimum vehicle | High-clearance recommended |
| Nearest town | Flagstaff, Arizona |
| Land manager | Coconino National Forest |
| Permit required | No |
| Cell service | Spotty |
| Water crossings | No |
| Dispersed camping | Yes |
| Official sources | fs.usda.gov |
| Start coordinates | |
| Find on Google | Search on Google → |
Location
Trail Conditions
No recent condition reports. Be the first to post one.
Log in to post a condition report.
Frequently asked questions
Can a stock Tacoma or 4Runner handle this trail without any mods?
Yes. The trail is dirt and gravel with no serious obstacles — a stock high-clearance truck or SUV is fine. Low-slung cars and minivans will scrape, so skip those.
When does the trail close, and is snow a real issue up here?
Best window is April through November. At 7,200 feet, snow and mud can shut this down well into spring and return early in fall — call Coconino National Forest before heading out if you're running the edges of that season.
Do I need a permit or pass to drive the trail and visit Lava River Cave?
No permit is needed for the forest road itself, but Lava River Cave requires a free recreation pass or America the Beautiful pass for entry — standard Coconino National Forest rules apply.
What's the hardest part of the trail and is there anything that might catch me off guard?
Nothing technically demanding here — it's an easy forest track. The main catch is the road can get rutted and loose after rain, and the final stretch into the cave area can be rough enough to rattle an unloaded rig.
Is there any water near the trail or cave for camping, and how far is the nearest gas?
No water sources on trail — pack everything in. Dispersed camping is available in the surrounding forest. Flagstaff is roughly 20 miles south and has full services including fuel.
Trail track
No GPX track for this trail yet. If you've driven it and have a track, contribute below.
Log in to contribute a GPX track.