Iron Horse State Park

Iron Horse State Park is a 110-mile trail that used to be part of the Chicago-Milwaukee-St. Paul-Pacific Railroad. (It's still shown as railroad track on Google Maps, if you want to see the route). It goes from Cedar Falls (near North Bend) over Snoqualmie pass to the Columbia River, just south of Vantage. The trail is well maintained and at an easy grade, with a surface of packed dirt and loose gravel. It crosses Snoqualmie Pass through the old mile-long railroad tunnel which is closed in winter and unlit, so bring a good flashlight. The trail is open year-round for any non-motorized use, except snow mobiles are allowed on a strip near North Bend. Several primitive camp sites are available along the route. See this Seattle PI article for a more detailed review: http://seattlepi.nwsource.com/getaways/101499/iron14.html