How did this rock “sink”?

Posted By Wolf Ridge Naturalist
December 11, 2017

Early in the week we were able to see a phenomenon normally isolated to spring. When soil freezes, the water inside it expands, pushing up and out in all directions. When the ice hits a large rock, it pushes it upward thus deforming the soil around it. This phenomenon is known as frost wedging. But since we’ve had thaws this ice has melted, dropping the rocks and leaving raised craters around them on the trails.

By Sam Anderson, Allison Hren, and Alicia Little