LaSalle County Nuclear Station Cooling Pond, also known as LaSalle Lake, is a 2,058-acre perched cooling lake located near Marseilles, Illinois. This man-made lake was constructed to cool the LaSalle County Nuclear Power Generating Station and opened for public fishing in 1987. The lake's unique design, with levees higher than the surrounding land, creates potentially hazardous conditions for boaters and paddlers.

The lake features an 11-mile shoreline composed entirely of dirt and rock excavated during construction. It has an average depth of 15 feet, with some areas reaching 70 feet deep. Water clarity typically ranges from 2-10 feet.

Paddling on LaSalle Lake comes with significant safety considerations. Due to its perched construction, winds and waves can become extremely strong with little notice. All watercraft must be powered by gasoline engines, with a 40 mph speed limit in effect. Sailboats, rowboats, surfboards, and sailboards are prohibited, as are swimming and water skiing. Paddlers should exercise extreme caution and be aware of areas marked by bright orange buoys.

The lake is open seasonally, typically from March 15 to October 15, from 6:00 AM to sunset daily. Three concrete boat ramps provide access, with a paved parking lot accommodating 140 vehicles with trailers. The boat launch is ADA accessible.

LaSalle Lake offers excellent fishing opportunities, with popular species including blue catfish, largemouth and smallmouth bass, hybrid striped bass, and bluegill. The entire shoreline is lined with rip-rap, providing good habitat for various fish species.

Paddlers should be aware that zebra mussels are present in the lake. There are no lodging facilities directly on the lake, but options are available in nearby towns. The lake's proximity to the nuclear power station gives it a unique character among Illinois paddling destinations.