|Red Hill near Fossil Falls, with the crest of the Sierra Nevada in the distance.|
A few streams originate near the crest and flow into the Owens Valley. For years these streams fed the Owens River which filled Owens Lake, covering just over 100 square miles to a depth of 30 feet or so. From there the water could only evaporate or sink into the ground. Today the lake is dry, the victim of water diversions that sent Sierra water to Los Angeles. The lake would have to fill to a depth of 200 feet before spilling over into the next basin at China Lake. That would require much more precipitation than happens in the present day.
|Upstream portion of Fossil Falls|
The rivers were like a highway for life. At some point in time, they connected with the Colorado River and numerous species of fish entered the waterways: trout, chub, pupfish and many others established populations in the streams and lakes of the Sierra and eastern desert valleys. As the glaciers receded and disappeared, so did the rivers and lakes of the desert. The few fish populations that survived did so in springs and Sierra streams. For the most part, aquatic life withered away in the desert heat.
like the one at Mammoth Lakes, but in other places, the volcanism was less explosive. South of Owens Lake, there were a number of basaltic lava flows extruded within the last 130,000 years or so. Some of them crossed and blocked the Owens River. The rivers developed channels across the lava flows, and in one place, the waters poured over a forty foot wall, forming a waterfall.
The waters carved a channel in the solid basalt, and swirling gravel and boulders carved deep potholes. Fossil Falls, just a short distance off of Highway 395 near Red Hill cinder cone is what remains of this now extinct river. It is a fascinating place to explore, and was one of our stops on our journey to Death Valley a few weeks ago.
It had rained a week before our arrival and water stood in a few of the potholes. I took a close look, and the small pools were teeming with life. I couldn't get any good pictures, but a video I took shows the action. There are longish gray shrimp and some kind of very small swimming creatures at the water's edge. It's is amazing to see life persisting in the most difficult of environments.