Upper River Run is a 6 mile loop trail located near Winthrop, WA and is good for all skill levels. The trail is primarily used for hiking, walking, and snowshoeing and is accessible from December until March. 6.0 miles 500 feet Loop kid friendly hiking snowshoeing walking Expand Map Sign up now to see this map! Reviews (0)Photos (0)Recordings (2)No one has reviewed this trail yet. Be the first!