Powderhorn Lake
Powderhorn Lake
Powderhorn Lake Show map of Illinois Powderhorn Lake Show map of the United States
Location	Cook County, Illinois, United States[1]
Coordinates	41°38′27″N 87°31′53″W / 41.64083°N 87.53139°W / 41.64083; -87.53139
Basin countries	United States
Surface area	48 acres (19 ha)[1]
Average depth	17.4 ft (5.3 m)[1]

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.^[1] It is the centerpiece of the 192 acres (78 ha) Powderhorn Lake Forest Preserve, part of the Forest Preserve District of Cook County in Cook County, Illinois.^[1]

Powderhorn Lake drains into the Grand Calumet River, which is historically part of the Lake Michigan watershed. Man-made engineering now moves the Grand Calumet River’s water into the Cal-Sag canal and valley system, which drains into the Des Plaines River and ultimately into the Illinois River.^[2]

In 2007, 130 acres (53 ha) of the Powderhorn Lake forest preserve was designated as the Powderhorn Prairie and Marsh Nature Preserve, the only state of Illinois-designated nature preserve within the city limits of Chicago. 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. Human-powered boating and fishing are encouraged in the southern half of the lake, but are not permitted in the wildlife-refuge northern half.^[1] The boat launch is located on the southern border of the lake, off Brainard Avenue in the suburb of Burnham, Illinois.^[2]