The Dungeness watershed is located in the rain shadow of the Olympic Mountains. Despite being within a coastal region, agriculture here requires irrigation. The 31.9 mile-long Dungeness River drains 270 square miles, meeting the Strait of Juan de Fuca after it drops from the mountains and joins the Gray Wolf River. While the high peaks of the Olympics are steep and jagged, the foothills are smoother due to glacial activity, and the middle and lower watershed are flat and broad.
Sediments deposited in Dungeness Bay have formed the Dungeness Spit, which curves 5.5 miles into the bay. It is the longest natural sand spit in the United States. The Dungeness river mouth has migrated over time, which is common with braided streams, and the channels often shift during floods. Lower flows occur in late summer and fall, with high flows peaking in December and June. Relatively little water is stored in the upper watershed and precipitation is the primary water supply, causing high flow variability.
- Counties: Clallam, Jefferson
- National Estuary Programs: Puget Sound
- Other Watersheds Upstream: Puget Sound
- Other Watersheds Downstream: Crescent-Hoko