Dauphin Lake is located in western Manitoba near the city of Dauphin, Manitoba. The lake covers an area of 201 square miles (520 km2) and has a drainage basin of about 3,420 square miles (8,900 km2). The Mossy River drains the lake into Lake Winnipegosis. The basin is drained by seven major streams and has a total relief of 1,900 feet (580 m). The lake is located within the territory of three rural municipalities; in descending order of area they are the RM of Ochre River, the RM of Dauphin, and the RM of Mossey River.