Powderhorn Lake, within Illinois but close to the state line, is a 48 acres (19 ha) lake that is part of the sand wetlands of the Indiana Dunes, most of which are located in the nearby state of Indiana.

The nature preserve protects an overall dune and swale landscape that contains parallel sandy ridges alternating with low-lying woodlands.

In the Indiana Dunes ecosystem as a whole, these landscapes foster tallgrass prairies, sedge meadows, savannas, and woodlands.

[1] Powderhorn Lake is also managed by the Cook County Forest Preserves for small boating and fishing.

[1] The boat launch is located on the southern border of the lake, off Brainard Avenue in the suburb of Burnham, Illinois.