Unfolding mysteries at Lost Lake

Years ago I heard stories of large fish that lived just west of Santiam Pass in one of over 19 lakes in Oregon that harbor the name Lost Lake. Perhaps this is the most fitting lake for the name because it nearly vanishes from sight every year. The water migrates down through cracks in the ground causing the lake to empty out each summer.

Even so, I wanted to see for myself if the fish story held any bait. With a snorkel and mask, I surveyed the lake for fish, pulling myself through marshy areas of the lake searching for hidden trout. After a few passes around the lake with no luck I gave up my search, only to find my body covered in leeches as I left the water. I haven't been swimming there since.

Last year a set of mysterious sink holes in the lake gained media interest. Each year the majority of water from the lake drains down through sinkholes and disappears. Several reports speculate that the water empties into a lava tube beneath the lake, and likely finds its way to Clear Lake in due time. But some see a different possibility.

Matt Skeels, a knowledgeable caver from Bend, reports, "There is no lava flow that flowed into Lost Lake and ALSO flowed out in any quantity that allows for the creation of lava tubes, especially on what appears to be the wrong end of the lake (the northeast end). It's very likely this is a 'pothole' as seen in Central Oregon's Potholes Flow and others, where you have portions of the lava not inflating and creating collapse-like structures. These holes are great for draining water should it come to settle thousands of years later, just like it does now at Lost Lake."

One can easily see by crawling down into the sinkholes that they are not made of lava, the walls are lake-bed sediment. It is more likely that the water is filtering through cracks and fissures too small for a human body to pass through. That is, after the first few feet.

Arhreev Bauvnav, an active caver in Washington state, stopped by Lost Lake last year and once inside the first sinkhole that most people visit, found a way to crawl through a very tight passage that led beneath the lake approximately 45 feet, at which time the passage became too tight to follow. What he found, besides lots of frogs and newts, were a few side passages filled with sand, curves and bends in the passage and areas blowing strong air, an indication of more passage beyond the blockage.

On a recent visit to the lake, July 5, 2016, I found the first sinkhole was dry. There was a very good reason for this: a new sinkhole has appeared about 20 feet beyond the old sinkhole. The new hole measures four feet wide and over 10 feet long. It appears the side nearest the bank covered with grass collapsed into the new hole, opening up a new drain. The water is flowing directly back toward the old sink in line with Arhreev's sketch map and obviously following the same drainage.

The mystery at Lost Lake continues as more questions appear on the horizon. But for now, the lake is completing its annual cycle as the water washes down the drain.