Subsequently the mudflows drained into both the North Fork of the Stillaguamish River (at that time an outlet of the Sauk River) and Skagit Rivers.
The mountains provide a source for several major rivers in the east, including the Snohomish, Snoqualmie, and Stillaguamish, that in turn form major bodies of water to the west.
Mississippi River | River Thames | Amazon River | Columbia River | Hudson River | Colorado River | Potomac River | river | Ohio River | Missouri River | Delaware River | Murray River | River Tyne | Madeira River | Volga River | River Nene | River Clyde | River Trent | River Severn | Amur River | River Wear | Allegheny River | Red River | Dnieper River | Yarra River | Paraná River | River Tees | Fraser River | Yangtze River | Tocantins River |
Utsalady was a base from which settlers headed to the Stillaguamish and Skagit Valleys on the mainland.