Driving through the Snake River Canyon on US 30 between Hagerman and Twin Falls, it's easy to see how the Thousand Springs Scenic Byway got its name. An abundance of natural springs gush from the steep canyon walls and cascade into the river below. The water source is the Snake River Plains Aquifer, one of the largest groundwater systems in the world. It creeps through an area of several thousand square miles under southern Idaho's porous volcanic rock before emerging from the springs in the cliffs.
Today, hydroelectric projects divert some of the water. Thats why you wont see literally a "Thousand Springs." However, it is still an impressive sight.