Welcome to the Cascadia Bioregion Atlas!

This is a collaboratively written living atlas of the Cascadia Bioregion. New maps and layers will be added in the future.

A bioregion is a “bio-cultural region” defined by the natural geographic boundaries of ecosystems, watersheds, and human communities, rather than by political boundaries. Bioregions are a powerful concept for organizing regional identities and guiding locally appropriate management decisions. The Cascadia Bioregion encompasses the Columbia and Fraser watersheds, as well as other adjacent watersheds draining into the Pacific Ocean.