Rivers at RNSP are world-renowned for fishing and no less loved for recreation and sheer beauty. The Smith River, named for explorer Jedediah Smith, arises in the Siskiyou Mountains and flows through the parks' north section. It is now California's last major free-flowing river and is famous for salmon and steelhead. The Klamath River, also a salmon and steelhead river, crosses the midsection of these parks. Redwood Creek flows through the parks' southern section.

The three large river systems within the park -- the Smith River, the Klamath River, and Redwood Creek -- have cut deep gorges through the forest and mountainous terrain. Redwood Creek follows the Grogan Fault northwest, with many small tributaries. The Klamath River, the largest in the North Coast region, provides important habitat for wildlife along its banks and in its estuary. The Smith River is also important for wildlife and has been named a Wild and Scenic River.

Stream flow depends on the amount of rainfall in the parks. The rainy season usually stretches from October through April, but the Smith and Klamath rivers also receive water from snowmelt in the mountains to the east. Warm rains combined with snowmelt have caused floods, including the large flood of December 1964 which caused the highest record peak flow on Redwood Creek.

Though there are no natural ponds or lakes in the parks; there are lagoons and marshes, results of oceanic and tectonic processes. Also within the parks' boundaries are the estuaries at the mouths of the Klamath River and Redwood Creek. These estuaries provide several uses for humans and wildlife: a transition and nursery area for fish, valuable habitat for fresh and saltwater species, recreational area for park visitors and nearby communities, and a supply of water for farming and ranching.

Salmon and steelhead populations were severely diminished by past logging activities within Redwood Creek's watershed. Increased sediment loads as a result of increased erosion has altered the habitat of Redwood Creek. Today, these fish are attempting to maintain their presence in the creek, but very few of these fish are able to adapt to the ecological imbalance.

Find out more about wildlife of the rivers and streams.