Basalt Columns like “Rock Fence Posts” in Yellowstone

Yellowstone’s Calcite Springs

Calcite Springs. Photo by Gloria Wadzinski

Calcite Springs. Photo by Gloria Wadzinski

Calcite Springs (pictured above), in the Tower-Roosevelt area of Yellowstone, feature massive rock formations that look like rock fence posts. The Yellowstone River exposed the landscape’s violet past here. The orderly columns across the canyon are volcanic. Their formation is the same as its famous cousins – Devil’s Tower in northeastern Wyoming, and Devil’s Post Pile in eastern California.

Today, they tower over the Yellowstone River like like soldiers standing at attention.

[From an exhibit sign at the overlook] From vents in the Yellowstone Plateau lava welled up and flowed – a vast flood of fire 25 feet deep. 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.

Basalt Columns on Overhanging Cliff

You can see more columns along the roadside on Yellowstone’s Grand Loop near the Tower Falls area.

Overhanging Cliff by Greg Willis

Above: Overhanging Cliff by Greg Willis [CC-BY-SA-2.0], via Wikimedia Commons

Yellowstone’s Sheepeater Cliff Columns

Basalt columns can be seen at the Sheepeater Cliffs along the Gardner River between Mammoth and Norris.

Sheepeater Cliff columns. Photo by A Softer Answer

Above: Columnar basalt on Sheepeater Cliff by A Softer Answer [CC-BY-SA-3.0 or GFDL], via Wikimedia Commons