Maple

A summer trap net survey was conducted in Maple Lake by Lake Biological Monitoring and Assessment program staff beginning on August 4, 2025. Twelve trap nets were set along the shoreline in locations that encompassed multiple habitat types. Trap net sampling captured 12 species of fish, including two species that are intolerant of disturbance (i.e., Rock Bass and Smallmouth Bass). Bluegill comprised a majority of the catch by number, while Walleye and Yellow Bullhead comprised a majority by biomass. The trap net and nearshore data from July 2025 were combined with gill net data from a June 2025 survey to describe the fish community and provide a fish-based IBI (FIBI) score. The survey results will be considered when the biological health of the lake is assessed during the Chippewa River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency. Maple Lake provides recreational angling opportunities for Sunfish, Largemouth Bass, Northern Pike, and Walleye. Smallmouth Bass are also present in Maple Lake. You can help protect the fish community in Maple Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.

This nearshore survey was conducted during summer 2025 to assess populations of non-game species and small game fish using backpack electrofishing and seining. Backpack electrofishing and/or seining were conducted at 14 stations, representing a variety of habitat types, along the shoreline of Maple Lake. The survey was conducted during the five-year sampling window for intensive monitoring efforts within the Chippewa River watershed, and will be contributing to a watershed assessment process in coordination with Minnesota Pollution Control Agency. Sixteen species were collected during this survey. Six species (Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter, Mimic Shiner, and Smallmouth Bass) were considered "intolerant" and one species (Green Sunfish) was considered "tolerant" based on current tolerance classifications for Minnesota lakes. Nearshore catch data will be used along with gill and trap net catch data to develop an Index of Biotic Integrity (IBI) score, which is indicative of the health of Maple Lake.

Maple Lake is an 815-acre lake located approximately six miles south of Alexandria in Douglas County. The basin has a maximum depth of 78 feet and average depth of 16 feet. Due to Maple Lake's irregular shoreline and large bays, approximately half of the lake area is considered to be a littoral zone, which is that area less than 15 feet in depth. Water quality is very good. Water clarity has increased following establishment of zebra mussels and was measured at 16.5 feet during June 2025. Bottom soils are largely sand. Silt and sediment deposits occur in the back of bays. The lake supports a diversity of submergent plants. Due to clear water, plants have been found growing to a depth of 17 feet. Yellow water lilies occur in sheltered areas along the western shoreline. Highly valued hardstem bulrush is largely confined to undeveloped shoreline. Two improved public access sites are located on the north and east shorelines. A handicapped accessible, floating fishing pier has been installed near the north boat launch for shore-based fishing opportunities. A special harvest regulation for Black Crappie (10-inch minimum with a 5 fish bag) was implemented on Maple Lake in 1997. A standard lake survey was completed during 2025 to assess the fish community of Maple Lake. Black Crappie and Bluegill are abundant and size structure is good. Mean length of crappie caught in the spring panfish survey was 10.4 inches and lengths ranged from 5.3 to 12.2 inches. Sixty nine percent of the fish were longer than the 10-inch minimum length limit. Growth is below average compared to other Black Crappie populations in the Glenwood Area. Size structure of the Black Crappie population in Maple Lake was similar to other lakes in the Glenwood Area with similar growth rates, despite having a more restrictive harvest regulation. Mean length of Bluegill caught during the spring survey was 7.7 inches and the longest fish was 9.7 inches. Approximately half of the Bluegill caught were 8 inches and longer. Bluegill growth rates are near average, but Bluegill live to be quite old in Maple Lake. Fish up to 14 years old were collected. Northern Pike abundance decreased from the last survey but still remains high. Small Northern Pike are overly abundant. Northern Pike ranged from 10.3 to 31.9 inches but averaged only 18.9 inches. Largemouth Bass are also abundant, though low water levels during the bass sampling event limited catch rates during this survey. Past surveys indicate bass grow slowly but live to quite old ages and large sizes. Multiple Largemouth Bass up to 17 years old were caught during the 2019 survey and a number of these really old bass approached 20 inches in length. Smallmouth Bass have become established in Maple Lake after they were first observed during the 2019 survey. Smallmouth Bass caught during this survey ranged from 11.0 to 18.6 inches. Walleye are stocked to satisfy demand for this popular fishery. Stocking performance and survival of young Walleye into the population has proven to be inconsistent. Catch rates of Walleye have declined in recent surveys, which has been a consistent pattern in many lakes following zebra mussel establishment. Walleye gill net catch rates averaged 4.1 fish/net in 2025. Most of these Walleye correspond to fingerling stocked year classes, but the presence of fish from non-stocked years indicates some natural reproduction may be occurring. Average length of Walleye was 14.8 inches. The largest Walleye sampled was 26.7 inches in length. Anglers are encouraged to harvest the surplus of smaller pike under 22 inches to improve predator/prey balance and productivity of the fishery. Yellow Perch, preferred prey for bass, pike, and Walleye, are in short supply. If faced with limited perch, predators may shift their diet to other juvenile gamefishes. Young Walleye are an acceptable alternative for perch. Maple Lake was designated as an infested water after the discovery of zebra mussels in 2013. Recreational users should take necessary precautions to prevent further spread of invasive species. Drain all water and remove all aquatic vegetation from your boat and trailer when leaving any body of water.

Based on Minnesota DNR survey data, anglers target Walleye, Black Crappie, Hybrid Sunfish, Largemouth Bass, and Northern Pike in Maple. See the full species list above for catch rates, size structure, and quality scores.

Minnesota DNR records list public access for Maple. Check the DNR LakeFinder page for the launch type and directions before you go.

Maple has a maximum depth of 78 feet and a mean depth of 16.1 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Maple is from 2025.

Yes — Maple has confirmed zebra mussel. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.