Sammamish River Trail (Wikipedia) The Sammamish River Trail is a 10.1-mile (16.3 km) bike path and recreational rail trail in King County, Washington that runs along the Sammamish River from Blyth Park in Bothell to Marymoor Park in Redmond as part of the “Locks to Lakes Corridor.” It connects to the Burke-Gilman Trail at its northwestern end, and to the Redmond Central Connector at its southeastern end.