At 165 miles long, the Trinity River is the longest tributary of the Klamath River. It flows north west of Redding and is designated a National Wild and Scenic River. The Trinity is known for its runs of salmon and steelhead; the king salmon are available mid-July through October, when the steelhead arrive and typically stay through March. It's open year round, and the Fly Fishing Only Section (200 feet bwloe Lewiston Dam to the Old Lewiston Bridge) is open April 1-September 15.