On the east coast you have the AT- the Appalachian Trail here on the west coast we have the PCT- the Pacific Crest Tail. The PCT was designated one of the first scenic trails in the National Trails System authorized by Congress in 1968, and was dedicated in 1993. Traversing from (south to north) Mexico to Canada through California, Oregon and Washington. Now hikers can enjoy another amazing trail the 1200 mile Pacific Northwest National Scenic Trail (PNNST), running from the Continental Divide to the Pacific Ocean, ranks among the most scenic trails in the world. This carefully chosen path is high for the views and long on adventure. It includes the Rocky Mountains, Selkirk Mountains, Pasayten Wilderness, North Cascades, Olympic Mountains, and Wilderness Coast. The trail crosses 3 National Parks and 7 National Forests. Check out the article "America's Newest Long Trail" highlighting a 100+ miles section of the trail in northeastern Washington trail (Okanogan National Forest to Ross Lake) in the recent Backpacker Magazine (March.2012).
Take a look at the Pacific National Trail Association home page.