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Sisters, Oregon

Lost Lake

This lake in the Cascades lives up to its name, disappearing down a hole every spring. 

Every year, in the heart of Central Oregon’s Cascade Mountains, there is a lake that mysteriously drains down a hole.  It fills up to capacity each winter, quickly starts to drain every spring, and transforms itself into a quiet meadow by summer.

Lost Lake, near the small town of Sisters and the Hoodoo Ski Resort, is a 79-acre watery haven during the rainy months. Streams and creeks are running high and fast, and this mountain basin fills up like a bathtub. When the rains slow down, so do the streams, but the cycle of the lake doesn’t stop there. The water recedes, pours into a 7-foot wide hole, and simply disappears.

Geologists speculate the culprit is a collapsed lava tube created during a period of intense volcanic activity over 12,000 years ago.  The tube has formed a slow drain that feeds into the rock-hard honeycomb of old lava underfoot (or under-lake), the water running into a tributary of the McKenzie River and surrounding aquifer, eventually ending up 6 miles away in Clear Lake.

When Lost Lake is gulping water in winter it can keep up with the constant draining.  But by spring, when flow is low and the drain is wide open, the lake lives up to its name. One request: please don’t try and plug the hole. It won’t work, and it only makes more work for the Forest Service. They work hard enough already.

Know Before You Go

There is more than one Lost Lake in Oregon, so be sure you're heading to the right one. This one is about 25 miles northwest of the center of Sister (which is about 80 miles northeast of Eugene). Follow US-20 going west and turn right onto NF-835 that wraps around the lake. About half a mile along there is a Day Use parking area on your left, and the hole can be found off to your right. Lost Lake is also near Hoodoo Ski Area. It drains each year in early spring.