In 1962 and 1963, industrial accidents spilled 3.5 million gallons of oil into the Mississippi and Minnesota Rivers. The oil covered the Mississippi River from St. Paul to Lake Pepin, creating an ecological disaster and a demand to control water pollution.
Between 1913 and 1914 the Coon Rapids hydroelectric dam was constructed with the intent to provide power to Anoka County. The dam was shut down in 1966 after becoming too expensive to operate. It later became part of Minnesota’s environmental control program.