[2] The lake is named for General John Cook, who commanded a company of soldiers stationed there in 1862–63 following the Dakota War of 1862.

The lake's level is supported by pumping water from the Missouri River through a 24-inch pipe at the southwest end, transported over 1½ miles, which costs about $1,000 a week.

Lake managers reversed the pipeline flow to pump water back into the Missouri in order to prevent flooding of nearby homes and damage to city sewers.

[6] McCook Lake experienced severe flooding in June 2024 after three days of historically heavy rains fell north of the area.

Upstream communities North Sioux City and Dakota Dunes, acting on established flood abatement plans, built temporary levies designed to divert Missouri River floodwaters to McCook.[7].

[9] McCook flood response became an issue in 2024 when South Dakota governor Kristi Noem was nominated to head the future Trump Administration Federal Emergency Management Authority.