Crowley Lake is a reservoir on the upper Owens River in southern Mono County, California, in the United States.

John J. Crowley, "the desert Padre", who was a key figure in Owens Valley history and a local hero.

These formations feature spaced columns, some rising 20 ft (6 m) tall, spanned at the top with arches and resembling the arcades of Moorish architecture.

In 2015 geologists from UC Berkeley concluded that the formations are the result of snowmelt seeping down into volcanic ash from the catastrophic eruption of the Long Valley Caldera, then rising up again as steam.

The researchers counted nearly 5,000 such pillars, which appear in groups and vary widely in shape, size, and color over an area of 4,000 acres (1,600 ha).