If you look at a world map, Cascadia is shaped like a whale swimming south. British Columbia’s temperate rainforest forms the bulk of its body, along with Washington state, Idaho, and much of Oregon. Mountainous Vancouver Island is the pectoral fin. The tail extends north to the southern tip of Alaska, and the whale’s open mouth, facing south, just catches northern California. Tall, dense forests of pine, spruce, and cedar blanket the bioregion. Aquatic species, from barnacles to sea otters, thrive in the pockets of habitat created by the coastline’s…