The hidden water reservoir is shockingly larger than previously thought—holding more than half the volume of Lake Tahoe.

Oregon's Cascade Range mountains might not hold gold, but they store another precious resource in abundance: water. Scientists from the University of Oregon and their partners have mapped the amount of water stored beneath volcanic rocks at the crest of the central Oregon Cascades and found an aquifer many times larger than previously estimated—at least 81 cubic kilometers.

A team of researchers with the University of Oregon on Monday announced they have found a massive amount of water under the Cascade Mountains in Oregon.