Natural history

The oldest exposed rock forms in the watershed are Ruinite granite, which dates to 1400 million years before present. The watershed holds a diverse flora and fauna. Within this part of the Sierra Ancha Range there are notable disjunctive population

Disjunctive population

A disjunctive population, in ecology, is a colony of plants or animals, whose geographical locus is severed from the continuous range of the bulk of the species distribution. Although a disjunctive population may sometimes occur on an island, which creates physical separation via water, a large...

s of Coastal woodfern, Dryopteris arguta

Dryopteris arguta

Dryopteris arguta, with the common name coastal woodfern, is a species of wood fern. It is native to the west coast of North America, where it grows in oak woodlands and shady low elevation slopes in Southern California and north.-Description:...

; this fern is otherwise common in areas nearer the Pacific coast.