Watch Oregon’s Lost Lake Disappear Through a Hole in the Ground

Lost Lake in Central Oregon looks a bit like a draining bath tub.

Melted snow fills up the basin with water at the end of winter creating a lake. But at the bottom of the body of water is a giant hole that sucks down the water, much like the drain in a bath tub. The drain, an open lava tube, is one of many throughout the region, according to a report in The Bend Bulletin. The water is likely absorbed by material just below the surface.

A placid mountain lake in central Oregon lives up to its name, Lost Lake, by disappearing every spring. This year, video capturing the annual phenomenon has gone viral.

As the above video shows, Lost Lake drains rapidly through a six-foot (two-meter) wide hole in the lake's bottom, morphing into a quiet meadow in late spring. Early in the following spring, the lake fills up again, as snowmelt from the surrounding Cascade mountains accumulates faster than water can drain out through the hole.

That hole is really a lava tube—a geologic feature made when lava cools around the edges of a river of molten rock. After the hot lava drains away, it can leave an empty space. There are many such tubes crisscrossing the Cascades, a mountain range that was formed in large part by volcanism.

Lost Lake is about two hours southeast of Portland. Perhaps alluding to its mysterious nature, its Native American name is “Kwoneksamach,” or “unknown.” (Learn about sinkholes.)

Parts of Oregon, like most of California, are experiencing drought, although Linn County, where the lake is found, is in decent shape.