20642 Highway J
Ralls County, Mssouri
573-735-4097
The Joanna Dam project was first proposed in 1937 to control flooding in the Salt River valley. In 1962 Congress authorized the multi-purpose project in the Flood Control Act of October 1962. Actual construction of the dam began in 1970 and was completed in 1983. The dam was renamed after the death of Clarence Cannon, chairman of the House Appropriations Committee and longtime member of the U.S. House of Representatives.
The dam impounds the upper Salt River about 63 miles upstream from its confluence with the Mississippi River. Approximately 165 miles of the river and its tributaries were inundated creating the 18,000-acre Mark Twain Lake. 450,000 cubic yards of concrete were used in the construction of 138-feet tall, 1,940-feet long dam.
The Clarence Cannon Dam contains a hydroelectric power plant capable of producing up to 58,000 kilowatts of power, or enough to supply a town of 20,000 people. Shafts connect a generator to a turbine that is powered by falling water hitting turbine blades. As much as 5,400,000 gallons of water pass through the turbines each minute when the plant is operating at capacity. Visitors are welcomed to the Cannon Powerhouse to enjoy a self-guided tour with hands-on exhibits that explain how the plant operates, how electricity is generated, and how energy is used.
Besides the lake itself, the Clarence Cannon Dam and Mark Twain Lake area offers an additional 36,000 acres of natural area with recreational opportunities that include boating, hiking, camping, bird and wildlife viewing, swimming, fishing, camping, and hunting.
Visiting the Clarence Cannon Dam
There is no charge to visit the Clarence Cannon Dam
