Trona Pinnacles

This unique geological feature, called Trona Pinnacles, are located about 10 miles south of the mining community of Trona, in California’s desert. Rising out of the dried up bed of Searles Lake, the pinnacles are composed primarily of calcium carbonate, also known as tufa, and are very similarly to those found in Mono Lake.

The pinnacles vary in size and shape from short and squat to tall and thin. Some of the taller ones are as high as 40 meters.

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Photo credit: Tony Hoffarth/Flickr

The pinnacles formed underwater of what was then a chain of shallow inland seas stretching from Mono Lake to Death Valley including Searles Lake. Deep beneath Searles Lake, calcium-rich groundwater and alkaline lake water combined to grow tufa formations. This happened between 10,000 to 100,000 years ago, with different groups of pinnacles forming at different ages and elevation. The southern group, consisting of about 200 tufa formations, is the oldest with dates ranging from 32,000 to 100,000 years. The northern group is the youngest at 11,000 to 25,000 years old. These are the best examples of what are known as tufa towers with a variety of shapes—squat and stubby, long and massive, and short and conical. The tallest pinnacles are located in the small middle group containing about 100 spires.

The Searle Lake has since shrunk in size isolating the tufa towers in the middle of a many square miles of flat, dried mud. This other-worldly location has been used in dozens of hit movies including Battlestar Galactica, Star Trek V: The Final Frontier, and Planet of the Apes.

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