About below the Marmot gauge, the river receives Badger Creek from the left. It passes under Ten Eyck Road about from the mouth, flowing by the city of Sandy on the left, shortly thereafter and receiving Cedar Creek, home of the Sandy Fish Hatchery, from the left. At about from the mouth, the river turns away from Highway 26 and flows generally north-northwest for the rest of its course. About further downstream, the river passes Dodge Park on the right, receives the Bull Run River from the right and passes a second USGS gauge at RM 18.4 (RK 29.6). Shortly thereafter, Walker Creek enters from the right. Between and from the mouth, the Sandy River enters Multnomah County, curves back into Clackamas County, and re-enters Multnomah County. About further downstream, Bear Creek enters from the left, and the river flows around Indian John Island.