- The South Fork Skykomish River begins at the confluence of the Tye River and the Foss River, to the east of Skykomish. From the confluence the South Fork flows northwest. Near the eastern boundary of the city of Skykomish, the Beckler River joins it. To the west of the city of Skykomish, the Miller River joins it. Shortly before converging with the North Fork the river drops over Eagle Falls, followed by Canyon Falls and then, finally, Sunset Falls before its confluence with the North Fork.