After the death in office of California United States Senator Clair Engle in 1964, the lake was renamed after him.

Trinity Lake is located northwest of Redding, off of Highway 299 north-northeast of the Gold Rush mining town of Weaverville.

The Alps were formed in the late Jurassic Period by volcanic activity in the form of ultramafic and granitic plutons (igneous rock formed from super-heated magma cooling under the surface of the earth), and tectonic activity (the super continent of Pangaea was beginning to pull apart into two separate super-sized continents) and glaciation during frigid climate periods known as ice ages (land surface modified by action of glaciers).

Popular fishing includes that of smallmouth and largemouth bass, catfish, kokanee, rainbow and brown trout.

The California Office of Environmental Health Hazard Assessment (OEHHA) has developed a safe eating advisory for fish caught in Trinity Lake based on levels of mercury or PCBs found in local species.

Surrounding the lake, visitors enjoy hiking and camping in the pristine wilderness of the Trinity Alps and the Shasta-Trinity National Forest.

Black bears are common, so proper precautions must be taken to secure campsites, throw away garbage and store food safely.