Nature
Lava River Cave, about 14 miles west of Flagstaff in Coconino National Forest, is Arizona’s longest known lava tube at roughly 0.75 mile. Formed about 650,000 to 700,000 years ago when lava from a vent in Hart Prairie cooled around a moving core that later drained away, it preserves both ʻaʻā and pāhoehoe basalt inside. Discovered by lumbermen in 1915 and once called Government Cave, it remains open to the public year-round under United States Forest Service management. Its dark, cold interior and varied passage heights make it notable, while litter and graffiti led to a major cleanup and restoration effort in May 1991.
Hear stories like this as you drive
ExploreHere reads historical markers out loud as you pass them: over 325,000 stories across the US. No account needed.
4.7 · 800+ ratings · Free
FIND IT
Arizona · United States
