Slate Lake Cave, Coconino National Forest, Arizona

Slate Lake Cave is in Arizona's Coconino National Forest — a lava tube approximately 900ft long with multiple entrances via a collapse entrance. Estimated formation age: 1-6 million years old. Corrosion residue is embedded in the basalt walls and one section has an interesting lava bed passage. An upper entrance in the wall was spotted but not reached due to time.

Contact your local NSS caving grotto for information on visiting Coconino lava tube caves — locations are kept in secrecy for conservation.