See massive rock columns formed by lava flow 1.3 million years ago. They look like rock fence posts and can be found at the Tower and Sheepeater areas in Yellowstone.
Yellowstone's Calcite Springs
Calcite Springs, in the Tower-Roosevelt area of Yellowstone, feature massive rock formations that look like rock fence posts. The Yellowstone River exposed the landscape's violent past here. The orderly columns across the canyon are volcanic. Their formation is the same as its famous cousins - Devils Tower in northeastern Wyoming and Devil's Post Pile in eastern California.
Today, they tower over the Yellowstone River like soldiers standing at attention.
"From vents in the Yellowstone Plateau lava welled up and flowed - a vast flood of fire 25 feet deep," says an exhibit sign at the overlook. "As the lava cooled and contracted about 1.3 million years ago, it formed contraction cracks, producing hexagonal columns of basalt. The rock layers are a geologic photo album. Lava Flows and other dynamic events have become benign scenic features, frozen in time. Above the below the basalt lies a loose mix of gravel carried here by glacial meltwater."
Yellowstone's Sheepeater Cliff Columns
Basalt columns can also be seen at the Sheepeater Cliffs along the Gardner River between Mammoth and Norris.