Kaiser Wilderness 2007 Backpacking - Scott Toste's Sierra Nevada

2007 Kaiser Wilderness Backpacking Trip

Home > Kaiser Wilderness > 2007 Backpacking > Upper Twin Lake

UNDER CONSTRUCTION

Upper Twin Lake is a beautiful place in which to spend time. Its most interesting feature is that it has no surface outlet. Lake water drains into an underground cavern which exits some distance away. I don't know the exact geology of this place, but based on my limited amateur understanding and observation I would say the lake was formed by glacial action and erosion of a band of marble that passes through this part of the Sierra Nevadas. This marble band is visible in satellite photos and passes right through the Twin Lakes. On the ground you can see marble outcroppings in several locations as you walk along the trail from Potter Pass to Upper Twin Lake to George Lake. Marble is dissolved by water that contains carbon dioxide (the carbon dioxide forms a weak acid called carbonic acid). There is a nearby sink hole that I am guessing is a collapsed section of the cavern that drains the lake. It is an interesting place to explore, but I would warn against descending into the sink whole because of the numerous large and lose rocks.

Upper Twin Lakes is a great place to camp. But because it is not remote you will see a "lot" of people. If you continue on to George Lake you can find a bit more solitude.

Location:
[coordinates]; Elevation [feet]

View the Upper Twin Lake Panorama

Here I am refilling my water bottle. Always filter your water to avoid picking up a protozoan like Giardia. Being miles away from civilization is no time to get dysentery.

Scott standing on a marble vein.

The view as we left Upper Twin Lake and ascended the trail toward George Lake.

Scott standing next to what's left of an old giant pine tree.

Not far from George Lake.

The Cavern and Sink Hole at Upper Twin Lake

Gene standing at the edge of the sink hole.

This is as far as we could see down into the sink whole without actually descending into it.

Scott on the rim of t he sink hole.

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