Walked the Green River Trail from Fort Dent park in Tukwila north to it's end along W Marginal Pl S at about S 103rd. Total mileage along this stretch is 10.6 out and back round trip. The southern Interurban trail meets up at the Fort Dent park as well if you are looking for more mileage. Parking is easy at Fort Dent Park, (which is also the Starfire center where the Sounders play.) The north end stops at what appears to be an abandoned wetland park now inhabited by homeless folks at least part of the time. There are nice views of the Duwamish River along the entire distance including the confluence with the old Black River just north of the Starfire complex. Watch for abandoned bridge abutments and pilings from when flat bottomed boats routinely made the trip all the way up to the Black River. Saw a good variety of bird life and a couple sea lions way up river near the big Boeing offices. Cecil Moses Memorial Park makes a nice turn around - the final stretch north is pretty rough and doesn't offer an additional views. Don't miss the old Allentown Grocery and remnants of the old bridge at S 124th. A nice walk along the upper Duwamish between Southpark and Tukwilla. http://www.kingcounty.gov/services/parks-recreation/parks/trails/regional-trails/popular-trails/green-river.aspx https://en.wikipedia.org/wiki/Green_River_Trail