Although the Quillayute River is short, its large tributary rivers—the Sol Duc, Bogachiel, Calawah, and Dickey Rivers—drain the largest watershed of the northern Olympic Peninsula, 629 square miles (1,630 km2).

The city of Forks is so named due to the close convergence of the Sol Duc, Bogachiel, and Calawah Rivers.

In 1992 the spelling was officially changed to "Sol Duc" by the State of Washington Board on Geographic Names.

The Sol Duc flows generally west and northwest, collecting numerous headwater tributaries.

It passes Sol Duc Hot Springs, a resort spa built in 1912 and refurbished in the 1980s by the National Park Service.

Nearby is the Sol Duc Campground, and the Soleduck Ranger Station,[12] after which its valley becomes considerably wider.

Beaver Creek joins from the north near Sappho, after which the Sol Duc River begins to turn more to the southwest and south.

Washington State Route 110, called La Push Road, continues down the Sol Duc Valley.

[16] The North Fork Sol Duc River originates at 47°56′52″N 123°45′2″W / 47.94778°N 123.75056°W / 47.94778; -123.75056, on the west slope of Mount Appleton.

It flows generally northwest, joining the Sol Duc River near Fairholm, about 4 miles (6.4 km) southeast of Mount Muller.

[16] The South Fork Sol Duc River originates at 47°57′5″N 123°58′11″W / 47.95139°N 123.96972°W / 47.95139; -123.96972, on the west slope of Pine Mountain.

[18] Tom Creek joins less than a mile from the South Fork's confluence with the main stem Sol Duc River.

[16] In the early 20th century the logging potential of the northwest Olympic Peninsula drew increasing numbers of settlers.

In January 1921 a massive "blowdow" toppled trees over a wide region between the Sol Duc and Hoh River.

[19] Large wildfires burned through the forests of the upper Sol Duc Valley in 1907 and in the 1951 Forks Fire.

Wildfires in this area tend to spread quickly east to west while remaining narrow north to south.

Driven by high winds the fire spread west down the Sol Duc Valley at a rate of about 18 miles (29 km) in 6 hours.

Of the Quillayute's tributaries, the Sol Duc River is remarkable in its migratory fish diversity and health.