Approximately 700,000 years ago when molten rock erupted from a vent in nearby Hart Prairie, the mile-long Lava River Cave was formed. Today, visitors can explore the cave's cool, dark expanse by ...

Early herdsmen were using a volcanic lava cave to shelter from the fierce desert sun at least 7,000 years ago, reveals new research. Bones, etchings and other artifacts discovered in what is now ...