 The Cascadia bioregion contains 75 distinct ecoregions, and extends for more than 2500 miles from the Copper River in Southern Alaska, to Cape Mendocino in the South, and east as far as the Yellowstone Caldera and continental divide.Cascadian bioregionalism deals with the connected ecological, environmental, economic, and cultural ties that are prevalent throughout the U.S. Pacific Northwest and distance the area from their eastern counterparts.The argument is that those in Washington and Oregon in the United States have much more in common with those in British Columbia, Canada, than those in Washington D.C..