Traverse Creek Botanical Special Interest Area (SIA) was designated in 1988. The purpose of the designation was to protect its unique assemblage of plants as well as geologic and archaeological features.

The 220-acre SIA consists of a shallow valley surrounded by moderately steep serpentine hills. Serpentine soils predominate in the western and southern portions of the SIA. These soils generally have high levels of magnesium, nickel, and chromium. Only plant species tolerant of or adapted to these conditions are capable of growing here, thereby, giving rise to the unique plant assemblages. Soils derived from metamorphosed sedimentary rocks predominate in the canyon bottoms in the eastern and northern portions, where they overlay the serpentine bedrock. This diversity of soils contributes to the overall diversity of plant communities within the SIA.