After the Crowley Lake reservoir in California was completed in 1941, some column-like formations with cracks ringing around them were spotted on the eastern shore. Naturally, several theories arose on the origins of these columns. Some put forward the idea that the Crowley Lake columns were the result of volcanic activity. On the other hand, some others thought the wind or water eroded the stone to form these rising spirals.
In order to solve the mystery, a group of geologists from the University of California started to investigate the Crowley Lake columns. With the help of different methods and equipment, including X-ray analysis and electronic microscopes, they found tiny spaces throughout the columns. According to the findings, a large volcanic explosion that happened 760,000 years ago created the Long Valley Caldera that holds the lake today. So, it appears that the formation of the columns is related to a volcanic past.
As for the formation of the columns, researchers think that there was a snowfall while the tuff was still hot. So, the still-heated porous surface caused the melted snow to boil, creating the even spaces between the columns that appear today. Researchers estimate that there are up to 5,000 columns spread within a 2 to 3-square-mile area to the east of Crowley Lake reservoir. They also vary in color some of them are gray while others are reddish-orange.