Lewiston Lake, reservoir in Trinity County, California, US

Lewiston Lake is a reservoir in California, held back by a dam on the Trinity River that collects cold, clear water from the surrounding mountains. The lake stretches for several miles with shallow flats and deeper channels where trout congregate throughout the year.

Lewiston Dam on the Trinity River impounds Lewiston Lake; the reservoir is part of the Trinity River Division of the Central Valley Project. Its water is used for transbasin diversion to the Sacramento River, flood control and hydroelectric generation. The lake lies in the canyon between the Trinity Mountains and Marble Mountains.

Lewiston Lake lies in the canyon between the Trinity Mountains and Marble Mountains, within the Whiskeytown-Shasta-Trinity National Recreation Area and Shasta-Trinity National Forest. Access is from the towns of Weaverville and Lewiston in Trinity County. Fishing, kayaking and camping are the main activities; anglers should check the California OEHHA safe eating advisory for mercury and PCBs in fish caught here.

The lake is regularly stocked by California wildlife officials, ensuring a reliable fish population year-round for anglers. Many visitors report catching rainbow trout weighing over 5 pounds, which speaks to the consistency of good catches at this location.