In 1937 the Joanna Dam project was first proposed as an answer to many years of flooding by the Salt River. With support and expertise of many, including Representative Clarence Cannon, the multi-purpose project was authorized by Congress in the Flood Control Act of October 1962. The dam and the lake offer multiple benefits to Northeast Missouri including: hydroelectricity, flood Control, recreation, fish and wildlife conservation, water supply (shortage of existing ground water), navigation.

Clarence Cannon Dam and Mark Twain Lake provide opportunities for outdoor recreation - boating, swimming, fishing, picnicking, hiking and hunting. There are recreation areas equipped with facilities such as campgrounds, beaches, and picnic shelters, as well as areas that are being managed for wildlife habitat. All visitors can enjoy the 54,000 acres of land and water at Clarence Cannon Dam and Mark Twain Lake.

Camping is available in three U.S. Army Corps of Engineers developed recreation areas, at the Mark Twain State Park and in several private recreation areas around the lake. Camping fees and facilities differ in the areas, however most have electric hookups, showers, restrooms, sanitary stations, fire grills, picnic tables and playground equipment. Group camping areas and a number of individual campsites are also available on a reservation basis. Campfire programs are held throughout the summer at outdoor amphitheaters in the campgrounds and give visitors the opportunity to learn more about the natural and cultural history of the area. School, scout and other interested groups may schedule programs upon request. The Corps also assists groups who sponsor bass tournaments, jamborees and other special events at the lake.

With over 18,000 acres of water, Mark Twain Lake is a suitable location for any type of water recreation. Boaters can use numerous boat ramps located conveniently around the lake as well as two full service marinas. Developed beaches on the lake provide swimming conditions. Anglers will find catfish, bass, crappie, walleye, bluegill and sunfish. Timber has been left in the upper ends of the lake and in selected coves to improve fish habitat.

Mark Twain Lake also provides recreational opportunities for picnickers, hikers, and hunters. Hikers and backpackers can use the many miles of trails throughout the lake area. Wildlife blinds, food plots and small ponds enhance a hiker's chance of spotting a deer, bluebird or other wildlife inhabitants of Missouri. For hunters, there are thousands of prime hunting grounds easily accessible from hunter/fisherman parking lots located throughout the area.

The U.S. Army Corps of Engineers is updating the Mark Twain Lake Master Plan. The Master Plan is the strategic land use management document that guides the comprehensive management and development of all project resources throughout the life of a USACE project.  The Master Plan guides efficient and cost-effective management, development and use of project lands.  It is a vital tool for the responsible stewardship and sustainability of project resources for the benefit of present and future generations.  The Master Plan guides and articulates USACE responsibilities, pursuant to Federal laws to preserve, conserve, restore, maintain, manage, and develop project lands and waters and associated resources.  The intent of an updated Master Plan is to present a current inventory and assessment of resources, provide an analysis of resource use, and evaluate existing and future needs required to protect and improve the value of resources at a project. 

The current Mark Twain Lake Master Plan, last approved in 2015, needs revision to address changes in regional land use, population, outdoor recreation trends, and the USACE management policy. Key topics to be discussed in the revised Master Plan include revised land use classifications, new natural and recreational resource management objectives, recreation facility needs, and special issues such as invasive species management and threatened and endangered species habitat. The Master Plan revision WILL NOT address the technical and operational aspects of the lake related to regional water quality, shoreline management, or water level management. During the process, the team will collect data, conduct analysis, prepare a draft report (which will become available for public and agency comments), and ultimately finalize and adopt the new Master Plan.