Cottonwood

Cottonwood Lake is a 255-acre shallow basin, located just north of Donnelly on the Grant and Stevens County line. A public access is located along the northwest shoreline, with an adjacent picnic area and beach. Residential development is very limited. However, typical of many shallow lakes in western Minnesota, the majority of the watershed is in agricultural production. To improve water quality, this basin was chemically reclaimed in 1996 as part of the Niemackl Lakes Watershed Project, to remove undesirable fish species. Survey results indicate benefits of the reclamation are still evident, with the sampling of few undesirable species and improved water clarity (16 feet during this survey). Walleye continue to be abundant (10.0/gill net), with a very strong year class of young fish in the system. Additionally, growth is fast. Average length between both net types was 19.7 inches, with the largest sampled being 28.0 inches. Walleye fingerling stockings have taken place on an alternate year basis, however aging analysis indicates that recent year classes have predominately been from natural reproduction. Northern Pike relative abundance (5.5/gill net) is higher than recent surveys but is still moderate compared to other area lakes. Average and maximum length was 22.8 and 29.5 inches, respectively. Anglers are encouraged to harvest small Northern Pike. New Northern Pike regulations were implemented in 2018 to increase size structure. Cottonwood Lake is in the North-Central Zone, where all pike from 22 to 26 inches must be released. Anglers can keep 10 pike, but not more than two can be longer than 26 inches. Northern Pike taken by spearing follow the same rules, except one pike may be between 22 and 26 inches, or two larger than 26 inches. For more information see: https://www.dnr.state.mn.us/pike/index.html. Few Bluegill (0.3/trap net) and Black Crappie (0.7/trap net) were sampled, but they were large. No young fish were sampled, and reproduction appears to be inconsistent, which is similar to previous surveys. However, growth is very fast, and fish can achievable desirable sizes within a few years. A lack of submerged vegetation is likely limiting survival. The same is true for Largemouth Bass, which were sampled in limited numbers (13.6/hour), but ranged from 15.6 to 18.7 inches. Black Bullhead (0.2/gill net) were the only other species in the survey, which have remained at a low abundance since reclamation. Cottonwood Lake is currently not an infested water. Aquatic invasive species (AIS) are easily moved from infested to non-infested waters and can negatively affect lakes and fish populations. To avoid spreading AIS, lake users are required to remove all aquatic plants and animals from their watercraft and drain water from their boat before leaving the access. For more information regarding aquatic invasive species see the following: http://www.dnr.state.mn.us/invasives/aquatic/index.html.

Seasonal water chemistry samples were collected from May - September 2023 and an aquatic plant survey of Cottonwood Lake was conducted on August 16, 2023, by Index of Biological Integrity (IBI) Program staff. Chlorophyll-a and Total Phosphorous levels were above the impairment threshold for lakes similar to Cottonwood Lake. In general, most aquatic plants were poorly distributed, sparse, or absent from a majority of the lake and surveyors noted that submerged plants were only sampled in very shallow water and were covered in filamentous algae. Those plants that were most common included filamentous algae, coontail, and Sago pondweed, and all three are tolerant to turbidity. Results from this survey provide evidence that Cottonwood Lake may be impacted by stressors, as indicated by the poor distribution of aquatic plants and water quality measurements above the impairment thresholds for lakes. Results from this survey will be considered when the biological health of Cottonwood Lake is assessed during Mustinka River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

Seasonal water chemistry samples were collected from May - September 2023 and an aquatic plant survey of Cottonwood Lake was conducted on August 16, 2023, by Index of Biological Integrity (IBI) Program staff. Chlorophyll-a and Total Phosphorous levels were above the impairment threshold for lakes similar to Cottonwood Lake. In general, most aquatic plants were poorly distributed, sparse, or absent from a majority of the lake and surveyors noted that submerged plants were only sampled in very shallow water and were covered in filamentous algae. Those plants that were most common included filamentous algae, coontail, and Sago pondweed, and all three are tolerant to turbidity. Results from this survey provide evidence that Cottonwood Lake may be impacted by stressors, as indicated by the poor distribution of aquatic plants and water quality measurements above the impairment thresholds for lakes. Results from this survey will be considered when the biological health of Cottonwood Lake is assessed during Mustinka River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

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

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

Cottonwood has a maximum depth of 16 feet and a mean depth of 10.1 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Cottonwood is from 2024.

No invasive species are on record for Cottonwood in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.