Lake Martin is located in Tallapoosa, Elmore and Coosa counties in Alabama, USA. It is a 44,000-acre (178 km²) lake with over 750 miles (1,200 km) of wooded shoreline. An artificial reservoir, Lake Martin was formed by the construction of Martin Dam on the Tallapoosa River. The Martin Dam powerhouse is used to generate hydroelectric power for the Alabama Power Company. Construction on Martin Dam began in 1923 and was completed in 1926, creating what was at that time the largest man-made body of water in the world.