Molossian Institute of Volcanology
The Soda Lakes are two lakes located northwest of Fallon, Nevada. They occupy two basaltic maar volcanoes which may have erupted in the last 1500 years. The larger lake (called Soda Lake) is somewhat elongated, stretching 2 kilometers (1.2 mi) in length, while the smaller one (Little Soda Lake) is 200 meters (660 ft) across.
Also called "tuff cones", maars are shallow, flat-floored craters that scientists interpret have formed above diatremes as a result of a violent expansion of magmatic gas or steam; deep erosion of a maar presumably would expose a diatreme. Maars range in size from 61 meters (200 feet) to 1,981 meters (6,500 feet) across and from 9 meters (30 feet) to 198 meters (650 feet) deep, and most are commonly filled with water to form natural lakes. Most maars have low rims composed of a mixture of loose fragments of volcanic rocks and rocks torn from the walls of the diatreme.
Soda (as in baking soda and bicarbonate of soda) began to be "mined" at Soda Lake in the late 1860's. When it was cold it was allowed to precipitate out in the large evaporating ponds; when the weather was hot it was pumped from the lake into vats and the water allowed to evaporate in the heat. It was then heated in two steps in a furnace to get rid of impurities, like the many brine shrimp.
After Lahontan Dam was built, the water table rose and with it, Soda Lake, covering the soda works. Efforts were made to pump the water out of the lake to a depression a couple of kilometers distant, but that effort was soon abandoned. The Lake is now about 15 meters (50 feet) deeper than it was originally.
DIRECTIONS: To reach the Soda Lakes, drive east from Reno or Carson City, Nevada to Fallon, Nevada. Turn left off U.S. Highway 50 onto Lucas Road. Stay straight on Lucas Road even after it turns to dirt and turn right at the end of the fence line on the right hand side of the road. Stay on this dirt track as it generally heads northeast to the southwest shore of Big Soda Lake. Little Soda Lake is south of Soda Lake; follow the dirt roads south to its shore. A dirt road circles the edge of Soda Lake, traveling along the steep edge of the crater wall and offering excellent views of the lake and the ancient volcano remnants.