Bear Trap Cave is a remarkable lava tube hidden in the volcanic wilds of Idaho's Great Rift, on public Bureau of Land Management land between the Craters of the Moon and Wapi lava fields north of American Falls. It's a window into one of the most dramatic volcanic landscapes in the country — a place where you can literally walk inside the plumbing of an ancient lava flow.

The Bear Trap lava tube is astonishing for its scale: the cave is part of a tube that can be traced for nearly 15 miles across the desert. It formed roughly 15,000 years ago, making it older than the nearby Wapi and Craters of the Moon flows, and it's prized for its well-preserved volcanic features, from lava stalactites to the shelf-like “curbs” left along the walls. The accessible cave is a spot where the ceiling collapsed, opening a way down into the tube.

This is remote, rugged country in the Great Rift Backcountry Area — the largest, deepest, and most recent volcanic rift system in the continental United States. Come fully self-sufficient: bring at least two reliable light sources plus a backup, wear a helmet and sturdy boots, and add a layer, since the cave stays cool year-round. Watch your footing on the loose, rocky collapse, and never explore a lava tube alone.

There are no services out here and little to no cell coverage, so carry plenty of water, tell someone your plans, and bring a good map or GPS — the access roads off the Minidoka–Arco Road are remote desert tracks. Dispersed camping is available nearby for those who want to make a night of it under exceptionally dark skies.

For volcano buffs and adventurous cavers, Bear Trap Cave is a genuine Idaho original — a long, ancient lava tube in one of the West's great volcanic frontiers.