This group made efforts to study all of the physical, economic, and social aspects of the Kaskaskia River throughout the state of Illinois.

In 1938, Congress approved the Flood Control Act of June 28, 1938, which authorized a major reservoir at Carlyle, levees downstream, and a plan for the development of the Kaskaskia Basin, but World War II put a temporary halt to the construction of the Carlyle reservoir.

Tracks containing five bridges span the water between Keyesport and Boulder, dividing the upper and lower parts of the lake.

The Illinois Department of Natural Resources operates the Eldon Hazlet State Park and the Carlyle Lake Wildlife Management Area.

The lake is separated into two unequal parts by a 3.5-mile-long (5.6 km) railroad embankment, and five bridges, carrying the tracks of the Burlington Northern Santa Fe.