Lake Isabel is a reservoir located in the San Isabel National Forest in Pueblo and Custer counties, in Colorado, United States.

[3] The lake is open to fishing year round and is regularly stocked by Colorado Parks and Wildlife.

Available activities include fishing, hiking, camping and sledding in the winter.

[4] The community of San Isabel lies on the north side of the lake, in Custer County.

The earthen dam and reservoir were built in the 1930s to store water for the CF&I Steel plant in Pueblo.