This mile-long lava tube cave was formed roughly 700,000 years ago by molten rock that erupted from a volcanic vent in nearby Hart Prairie. The top, sides and bottom of the flow cooled and solidified first, after which the insides of the lava river continued to flow emptying out the present cave.
Ample evidence of how the tube was born is written in the rocks of which it is formed. Small wave-like undulations in the floor are the remains of ripples frozen in the last trickle of molten rock that flowed from the cave. Stone icicles hanging from the ceiling show where a final blast of volcanic heat caused the rock to partially re-liquefy and drip.
Dress appropriately when you come to visit, with warm clothes and sturdy shoes. The cave is as cool as 42° even in summer, and you may even find some ice inside. The rocks are always sharp and slippery, too. Bring two or three sources of light, in case one happens to fail, it can be very dark one mile from the nearest light source.
Portions of the cave which were defaced by graffiti, have been recently cleaned up. Today's more environmentally aware visitors take better care of such a unique resource and report vandals when they see them.
See also "Lava River Cave: A Natural Museum"
See more Lava River Cave photos on Flickr
At a Glance
||Flagstaff Ranger District - 928-526-0866
Location: About 14 miles north of Flagstaff on paved highways and graveled Forest Roads. Travel time is about 45 minutes.
GPS (Map): 35°20'32.2"N 111°50'08.2"W
Access: Drive 9 miles north of Flagstaff on US 180 and turn west (left) on FR 245 (at milepost 230). Continue 3 miles to FR171 and turn south 1 mile to where FR 171B turns left a short distance to Lava River Cave.
NOTE: Though the Lava River Cave is open year-round, FR 245 and/or FR171 may be closed in the winter for resource protection. In those cases, you will need to hike or ski in to the cave.
Click on map map image for printable view.
Season: You can visit Lava River Cave the year-round though you may need to ski to it in winter since Forest Roads 245 and/or 171 may be closed for resource protection. Temperatures inside the cave remain roughly the same summer and winter (between 35° and 45° Fahrenheit).
Attractions: Cool cave, lava flow, scenic drive, wildlife viewing
Facilities: Interpretive sign
- Wear warm clothes and sturdy shoes.
- Bring two or three light sources.
- Please don't deface cave surfaces.
- For overnight camping, camp at least 1 mile from the entrance of the cave.