Thousand Springs: The Lost Rivers Come Home

The waterfalls pouring from the canyon walls here along the Snake River have a remarkable origin story. Rivers in eastern Idaho near Craters of the Moon flow out over ancient lava fields and simply vanish into the porous basalt, disappearing underground. Those lost rivers travel through the Snake River Plain Aquifer, one of the largest groundwater systems in the world, for well over a hundred miles before they re-emerge here as springs cascading out of the canyon face.

Some of the largest springs in the United States are in this stretch, and the water surfaces cold and steady year-round. Oregon Trail emigrants passed these cliffs in the eighteen forties, but most were too focused on getting to Oregon to stop and wonder where all that water was coming from. Thousand Springs State Park was assembled from several smaller units in two thousand five.