The Oregon Cascades have multitudes of where water flows out of the earth, areas called 'springs'. The Cascades also have a few locations in which the opposite event happens: water flows out of lakes and ponds and flows into holes and disappears underground into subterranian lava tubes.
Lost Lake is one of those locations in which the water level slowly seeps away over the warmer months. The lake slowly drains and a creek is all that is left, thus the lake goes 'missing' during the warmer months. In the winter and spring the water level is high enough that the internal waterfall is quite stunning. During summer months the land surrounding the lava tube is dry.
According to retired geologist Dave Kretzing, this area was burried in layers of ash and glacial gravels and then more volcanic ash. This makes it a geological lasagne with some holes in the top. The lava tubes around here were created by the downhill flows of lava about 12,000 years ago. As the lava flowed it began to cool and solidify on the top and sides. Once the eruption ceased, the tube emptied and drained, and a new lava tube cave is left behind. As the rock cooled, the inner surface of the tube cracked and collapsed, producing openings to the surface.
One study showed that water flowing into the tube turned up 5-7 years later at Clear Lake. If you have a chance to stop by Clear Lake, it is worth the stop at the Clear Lake Resort. Take a few hours and rent a row boat and view the incredibly clear waters.
To claim this cache please message the cache owner with the following information:
1) Date of your visit
2) What is the distance from the water's edge to the main drain? If the water is flowing into the main lava tube drain, desribe how high the water is around the edge of the main drain.
3) What is the shape of the main drain hole? How far across is it from side to side?
4) What is the shape of the nearby drain hole? How far this second drain hole from the lake water? 5) What evidence can you see of volcanic activity in the area?
5) While photos are not required, it is fun to see pictures of Geocachers! Please feel free to post pictures of this find.
Learn more about the lava tube drains at: (1) http://www.livescience.com/50749-lost-lake-lava-tube.html (2) https://en.wikipedia.org/wiki/Lost_Lake_(Santiam_Pass,_Linn_County,_Oregon) (3) Fire and water: Volcanology, geomorphology, and hydrogeology of the Cascade Range, central Oregon (PDF). GSA Field Guides (Report) 15 (Geological Society of America). 2009. pp. 539–582.