The Sol Duc flows generally west and northwest, collecting numerous headwater tributaries. Its length to its most distant headwater tributary is just over . Runoff was monitored at multiple stations in the headwater streams above Pajarito Canyon. Dams are listed in order from headwater (Upper Elk Lake) to mouth (Kootenay River, BC). Dams are listed in order from headwater (Purcell Mountains) to mouth (Kootenay River, BC). Dams are listed in order from headwater (Canadian Rockies) to mouth (Kootenay River, BC). Dams are listed in order from headwater (Canadian Rockies) to mouth (Columbia River, BC). Dams are listed in order from headwater (near Mount Dawson) to mouth (Kootenay River, BC). Dams are listed in order from headwater (Keechelus Lake, WA) to mouth (Columbia River, WA). Dams are listed in order from headwater (Timpanogas Lake, OR) to mouth (Willamette River, OR). Dams are listed in order from headwater (Clear Lake, OR) to mouth (Willamette River, OR). Dams are listed in order from headwater (Columbia Lake, BC) to mouth (Pacific Ocean, OR/WA). Headwater erosion rates are estimated at . The farthest headwater is the North River in the Mesabi Range at Hibbing, Minnesota. The river's first diversion is here at its headwater.