Trail maps for the Pacific Northwest nwjeepn.com/WAtrails.htm
Washington Department of Natural Resources www.dnr.wa.gov These folks control the few trails we have access to here in Washington (state of).
After seeing Oregon’s Backcountry Discovery Route, some guys put together one for Washington. 600 miles from Oregon to the Canadian border. http://www.wabdr.com/ Mostly on upaved dirt roads, looks like a lot of fun. They have put together gps waypoints for the run and you can see a map on the website.