The area is characterized by deep, rough canyons, sharp rock ridges, and clear, rushing mountain streams and rivers.

The Kalmiopsis Wilderness is part of the Klamath Mountain geologic province of northwestern California and southwestern Oregon.

The eastern half is part of the Josephine "ultramafic" sheet, meaning it has a very high iron and magnesium content.

[1] Diversity of topography and geology provide excellent habitat for a wide variety of botanical species.

The plant is a relict of the pre-ice age and the oldest member of the Ericaceae Family, and is the namesake of the Kalmiopsis Wilderness.