Madison Lake is a medium-sized lake of 1,446 acres located in south central Minnesota, east of Mankato. The lake has a maximum depth of 59 feet and 12 miles of shoreline. Nutrient levels in Madison Lake are high, resulting in frequent algae blooms and low water clarity, typically less than one meter in summer. This reduced clarity limits aquatic plant growth, though curlyleaf pondweed is abundant in shallow areas during spring and early summer.

The lake is known for its walleye population and sustains heavy angling pressure. Other fish species include crappies, sunfish, northern pike, bass, and bullheads. Madison Lake is unique as the only inland lake in Minnesota with a population of gizzard shad. Wildlife enthusiasts may spot loons on the water.

Bray Park, located on the southeastern shore, offers access for paddlers with a boat landing dock and fishing dock. The park also provides camping facilities, including RV and tent sites, as well as a log cabin that can be reserved for gatherings. A 0.7-mile paved nature trail and a 1.4-mile primitive footpath with a 70-foot swinging bridge over a ravine offer additional recreational opportunities.

Paddlers should be aware that high nutrient levels can lead to potentially harmful algae blooms, particularly in summer. The lake's productivity and frequent algae may impact the aesthetic experience. While there are no specific paddling routes or restrictions, paddlers should exercise caution around fishing boats, as the lake is popular for angling.