Once upon a time, on the eastern shore of Crowley Lake in Mono County, California, there existed a group of unusual stone columns that few people knew about. These columns, standing up to 20 feet tall and connected by high arches, resembled the ruins of an ancient Moorish temple. They had been buried and hidden for millennia until the powerful waves of the reservoir began eroding the softer material at the base of cliffs made of pumice and volcanic ash.
For decades, these stone columns were considered little more than curiosities along the eastern shore of the Los Angeles Department of Water and Power reservoir, best known as a trout fishing hotspot about 10 miles south of Mammoth Lakes. However, a recent study at UC Berkeley has unveiled the mysteries surrounding the origins of these columns.
Researchers have determined that the columns were created by cold water seeping down and steam rising up from the hot volcanic ash ejected by a cataclysmic explosion 760,000 years ago. “These columns are spectacular products of a natural experiment in the physics of hydrothermal convection,” said Noah Randolph-Flagg, 25, a PhD candidate and the lead author of the study, in an interview.
The blast, 2,000 times larger than the 1980 eruption of Mt. St. Helens, created the Long Valley Caldera, a massive 10-by-2-mile sinkhole that includes the Mammoth Lakes area. It also covered much of the eastern Sierra Nevada range with a coarse volcanic tuff.
Randolph-Flagg stated that the researchers not only discovered the origin of the columns but also learned a great deal about the surrounding landscape. “They have a lot to tell us about what the region was like before and after the caldera exploded, and about how volcanoes can change local climate,” he said.
The columns began forming as snowmelt seeped into the still-hot tuff. The water boiled, creating “evenly spaced convection cells similar to heat pipes,” according to the study to be presented next month in San Francisco at an American Geophysical Union meeting, the world’s largest conference in geophysical sciences. Analyses by X-rays and electron microscopes of samples of the columns found that tiny spaces in these convection pipes were cemented into place by erosion-resistant minerals.
Randolph-Flagg estimates that as many as 5,000 columns exist within a 2- to 3-square-mile area east of the lake. They appear in clusters and vary in size and shape. Many are gray, straight as telephone poles, and encircled with horizontal cracks about 12 inches apart. Some are reddish-orange in color. Some are bent or all tilting at the same angle. Still others are half-buried and resemble the fossilized backbones of dinosaurs.
Next year, the Department of Water and Power will begin ferrying students to the site as part of an “effort to further educate the public about these invaluable natural resources,” said Amanda Parsons, a spokeswoman for the utility. Edward W. Hildreth, a research geologist with the U.S. Geological Survey and an expert on the history of the Long Valley Caldera and the chemistry of its tuff, welcomes the sudden interest in the columns. They can be reached by boat, on foot, or by four-wheel-drive vehicles.
Further analysis could help scientists better understand how quickly the columns solidified and the chemistry and temperatures that produced their spacing, width, height, and composition. Among other researchers investigating the columns is Robin Wham, 62, a graduate student in geology at Cal State Sacramento, whose proposed thesis involves mapping their precise locations and comparing their characteristics to those of similar formations in New Mexico and Mexico.
And so, the magical columns of Crowley Lake are not just natural curiosities, but also historical witnesses, telling the story of a land that has experienced cataclysmic upheavals and transformations over millions of years. Recent studies and discoveries have opened a new chapter in scientific knowledge, while also sparking interest and celebrating the wondrous beauty of this natural marvel.
