After the most-recent glaciation ended, about 12,000 years ago, plants started to re-colonize the Island of Newfoundland. They slowly spread over the island, covering most of the limestone bedrock of the Northern Peninsula with soil and plants. Now, the limestone is almost completely blanketed with forest and wetlands. Only tiny portions of limestone in the most exposed places (coastal headlands, mountain tops, and cliffs) remain without a layer of soil and plants—these are the limestone barrens.

As water freezes, it expands slightly. Over centuries, frost has cracked exposed limestone bedrock into tiny fragments that look like driveway gravel. It is very difficult for trees and shrubs to grow in this thin layer of gravel, and that makes it an important refuge for the slow-growing arctic plants that once colonized all of the Island of Newfoundland. They have been pushed out of the rest of the island by trees and shrubs, and now only survive on the limestone barrens.