Lake Mary Ann is situated about 5 kilometres (3.1 mi) north of Tennant Creek, Northern Territory just off the Stuart Highway. It is a man-made dam where some water sports can be conducted such as swimming or canoeing, surrounded by landscaped grassy areas on one side and natural bushland on the other. Council is currently spending half a million dollars as first stage of a major upgrade to the facility. Originally the site was investigated with a view to increase the water supply for Tennant Creek and Peko Mine in the late 1940s, and later again in the mid-1950s. In 1977, several local residents proposed that a recreational dam could be constructed close to Tennant Creek. The NT Government supported the proposal and construction commenced during 1979/80. It was originally called the Mary Ann Dam.
In 2014, The Federal Court determined seven native title claims in the area of Lake Mary Ann covering 37,000 square kilometres.