Pioneers crossing this parched landscape were glad to find any available water. Most water is absorbed like a giant sponge when it reaches the lava fields, but here small creeks to the north cover the porous lava rock with sediments that impound Lava Lake. Beneath the surface of the lava rock, the thick walls of caves may provide enough insulation to retain winter’s ice, and rare waterholes sometimes form on the surface over these plugs of ice. Most water flowing from the mountains or falling on the plains is absorbed by the lava rock, creating a Lake Erie-sized aquifer deep beneath the surface. The Eastern Snake River Plain Aquifer helps Idaho’s famous potatoes thrive and provides drinking water for many communities in southern Idaho.