The concept of Cascadian bioregionalism is closely identified with the environmental movement. In the early 1970s, the contemporary vision of bio-regionalism began to be formed through collaboration between natural scientists, social and environmental activists, artists and writers, community leaders, and back-to-the-landers who worked directly with natural resources. A bioregion is defined in terms of the unique overall pattern of natural characteristics that are found in a specific place. The main features are generally obvious throughout a continuous geographic terrain and include a particular climate, local aspects of seasons, landforms, watersheds, soils, and native plants and animals. People are also counted as an integral aspect of a place’s life, as can be seen in the ecologically adaptive cultures of early inhabitants, and in the activities of present day reinhabitants who attempt to harmonize in a sustainable way with the place where they live. Cascadian bioregionalism deals with the connected ecological, environmental, economic and cultural ties that are prevelent throughout the Pacific Northwest and distance the area from their eastern counterparts. The argument is that those in Washington and Oregon have much more in common with those in British Columbia than those in Washington D.C. An argument which continues to gain ground as we enter a more global age, and as efforts to create integrated transportation and economic systems, stem pollution and global warming, and support sustainable alternatives increasingly requires the commitment of larger regional players.
The Cascadia Bioregion also referred to as the Pacific Northwest Bioregion) encompasses all or portions of Washington, Oregon, Idaho, California, Nevada, Wyoming, Montana, Alaska, British Columbia, and Alberta. Bioregions are geographically based areas defined by land or soil composition, watershed, climate, flora, and fauna. The Cascadia Bioregion claims the entire watershed of the Columbia River (as far as the Continental Divide), as well as the Cascade Range from Northern California well into Canada. The delineation of a bioregion has environmental stewardship as its primary goal, with the belief that political boundaries should match ecological and cultural boundaries.
The area from Vancouver B.C. down to Portland has been termed a megaregion by the U.S. and Canadian governments, especially along the 'Cascadian Corridor'. Megaregions are defined as areas where "boundaries begin to blur, creating a new scale of geography now known as the megaregion. These areas have interlocking economic systems, shared natural resources and ecosystems, and common transportation systems link these population centers together. This area contains 17% of Cascadian land mass, but more than 80% of the Cascadian population. Existing US and Canadian borders continue to be broken down in the face of further economic, political and cultural integration which such programs as the enhanced drivers license program - which can be used to get cross the Canadian border within Washington and British Columbia.