Monson

A standard survey was conducted during late May to mid-June of 2024 in Monson Lake. Various survey components included spring electrofishing for Largemouth Bass, May trapnets for Bluegill and Black Crappie, June gillnetting for all species and vegetation transects. A targeted survey is generally used for sampling a specific kind of fish or time of year (i.e., spawning season, fall season, etc.) unlike a standard survey which samples a wider range of fish species during the summer months using standard methodology (i.e., standard time of year, set sampling stations, taking water clarity readings and oxygen/temperature profiles, etc.) and gears (i.e., lake survey gillnets, trapnets and possibly spring electrofishing for Largemouth Bass). Monson is a small sized (208 acres), shallow (21 feet maximum depth), and moderately productive lake located in Swift County. Monson Lake State Park is located along the east side of the lake. Residential development is limited to 5 homes and 2 recreational vehicles along the south, north and west shore areas. The public access and shore fishing pier are located on the east side in the state park. Usage of Monson State Park and the corresponding public access is generally low compared to nearby Sibley State Park on Lake Andrew. The surrounding watershed is comprised of mostly agricultural row crops with small areas of woodland, grassland, pasture, and wetland areas. The immediate shoreline area consists mostly of undeveloped woodlands (hardwood trees) with small to moderate areas of wetlands, row crops, and grassland. Agricultural row crop runoff (via inlets) is the primary source of nutrient pollution into Monson. Nutrient levels were high (total phosphorus=0.063 ppm, Chlorophyll a=53.5 ppb) during 2015 in Monson. There are three small sized inlets (northwest, northeast, and south shores) that flow into Monson. The Monson outlet connects to West Sunburg Lake, which is a shallow, productive and sometimes susceptible winterkill lake. Fish movement is possible between West Sunburg and Monson during high water levels, which has resulted in excellent sunfish growth and good fishing in West Sunburg after several mild winters. A winterkill probably occurred in the connected West Sunburg Lake in February of 2019 and perhaps during the 2022-23 winter. Water levels were above normal during the 2024 summer. Dissolved oxygen was 8 ppm or greater down to 20 feet deep during mid-June. Water clarity (secchi reading) was good (12.0 feet) on June 10, 2024. Blue-green algae blooms can be common during the mid to late summer months in Monson Lake. Submergent vegetation is dense and diverse with water star-grass, northern milfoil, various pondweed species (narrow-leaf, curly-leaf, clasping-leaf, bushy, Fries", sago pondweed, Illinois, etc.), coontail, water moss, and filamentous algae present in Monson. Emergent and near shore terrestrial vegetation are also abundant and diverse consisting of various bulrush species, cattail species, arrowhead, swamp milkweed, and reed canary grass scattered throughout the bay, shoreline, and island areas. Shoalwater substrates are varied with sand, silt, boulder, gravel, rubble, detritus, muck and clay. Black Crappie abundance was low in 2024 survey nets (2.00 fish/gillnet, 0.44 fish/trapnet). The historical average catch rates (1982-present) are 1.36 fish/gillnet and 0.68 fish/trapnet for Monson. The Black Crappie average sizes were small for both gillnets (5.90 inches, 0.13 pounds) and trapnets (4.82 inches, 0.06 pounds) in 2024. The largest Black Crappie captured was 8.03 inches. Black Crappie growth rates were above the Spicer Area normal ranges for ages 1-2. The 2023 year class comprised 70% of the 2024 gillnet and trapnet catch. Bluegill abundance was low in 2024 (5.44 fish/trapnet) compared to the historical average catch rate (15.63 fish/trapnet) for Monson. The 2024 Bluegill average size was small (0.13 pounds and 5.08 inches) from trapnets. The Bluegill historical average weight is 0.23 pounds from trapnets. Approximately 10% of the Bluegill captured were 8.00 inches or larger in the 2024 survey nets. The largest Bluegill captured was 9.02 inches in 2024. The largest Bluegill captured was 11.81 inches (about 2 pounds) in the 2010 survey, but only 6.42 inches in the previous 2019 survey. Bluegill growth rates were above the Spicer Area normal ranges for ages 1-4. The 2022 year class comprised 69% of the 2024 gillnet and trapnet catch. Largemouth Bass were abundant (65.50 fish/hour) in the 2024 pre-spawn spring electrofishing. A previous 2015 Largemouth Bass spring electrofishing survey sampled low numbers (17.29 fish/hour). The 2024 Largemouth Bass average size was large (1.97 pounds and 14.18 inches) from spring electrofishing. The largest Largemouth Bass captured was 19.80 inches during 2024. Approximately 54% of the Largemouth Bass captured were 15.00 inches or larger in the 2024 spring electrofishing survey. Largemouth Bass growth rates were near or above the Spicer Area normal ranges for ages 1-8. Approximately 61% of all Largemouth Bass captured were 5 years or older from the 2024 spring electrofishing survey. Northern Pike abundance was high in 2024 (9.67 fish/gillnet) compared to the historical average catch rate (5.45 fish/gillnet) for Monson. The 2024 Northern Pike average size was small (2.28 pounds and 21.50 inches) from gillnets. The Northern Pike historical average weight is 2.61 pounds from gillnets. The largest Northern Pike captured was 31.10 inches in 2024. Approximately 24% of Northern Pike were 24.00 inches or larger in the 2024 survey nets. Northern Pike possession limit regulations for Monson in the North-central Zone are as follows: anglers can keep 10 Northern Pike, but not more than two Northern Pike longer than 26.00 inches; and all from 22.00 to 26.00 inches must be released. Northern Pike taken by spearing follow the same rules except one Northern Pike may be between 22.00 and 26.00 inches or two larger than 26.00 inches. Walleye abundance high in 2024 (9.00 fish/gillnet) compared to the historical average catch rate (4.80 fish/gillnet) for Monson. The 2024 Walleye average size was moderate (1.53 pounds and 15.41 inches) from gillnets. The Walleye historical average weight is 2.18 pounds from gillnets. The largest Walleye captured was 27.28 inches. Approximately 30% of the Walleye captured were 15.00 inches or larger in the 2024 survey nets. Walleye growth rates were above the Spicer Area normal ranges for all ages. The 2022 year class (fry stocked) comprised 58% of the 2024 gillnet and trapnet catch. We saw abundant numbers of yearling/adult Walleye in the 2024 spring electrofishing survey (107.00 fish/hour, 7.95 inches average). Approximately 92% of these Walleye caught were from the 2023 year class in the spring electrofishing survey. Walleye natural reproduction in Monson is generally infrequent and insignificant based on previous fall and summer surveys. Walleye were recently stocked into Monson during 2018 (231,135 fry; 28 fingerlings, 2 pounds; 1,441 yearlings, 371 pounds; 29 adults, 39 pounds), 2020 (448 yearlings, 298.5 pounds; 70 adults, 139 pounds), 2022 (71,590 fry), 2023 (50,842 fry; 3,480 fingerlings, 145 pounds) and 2024 (50,967 fry). Yellow Perch abundance was moderate in 2024 (8.00 fish/gillnet) compared to the historical average catch rate (10.96 fish/gillnet) for Monson Lake. The 2024 Yellow Perch average size was small (0.09 pounds and 5.82 inches) from gillnets. The Yellow Perch historical average weight is 0.21 pounds from gillnets. The largest Yellow Perch captured was 7.99 inches in 2024. Yellow Perch were recently stocked in 2021 (7,632 adults, 424 pounds) and 2022 (3,338 adults, 210 pounds). Black Bullhead abundance was moderate in 2024 (35.67 fish/gillnet), but below the historical average catch rate (87.21 fish/gillnet) for Monson. Black Bullhead abundance in the 2024 trapnets (6.78 fish/trapnet) was also below the historical average (20.66 fish/trapnet). The 2024 Black Bullhead average size was large (1.30 pounds and 12.83 inches) from gillnets. The Black Bullhead historical average weight is 0.90 pounds from gillnets. The largest Black Bullhead captured was 15.04 inches in 2024. Yellow Bullhead abundance was high in 2024 (3.00 fish/gillnet) compared to the historical average (0.52 fish/gillnet). The Yellow Bullhead average size was large (1.15 pounds, 12.60 inches) from gillnets. The largest Yellow Bullhead captured was 14.72 inches in 2024. Current fish management activities on Monson include monitoring the fish population on a periodic basis, protecting aquatic vegetation through the permit process, assisting aquatic plant management and enforcement personnel in educating boaters and monitoring access sites for potential invasive species introductions, participating in local watershed initiatives, and stocking various fish species as warranted. The Monson fishery will be sampled in the 2029 summer for all fish species.

A standard survey was conducted during mid-June of 2019 in Monson Lake. A targeted survey is generally used for sampling a specific kind of fish or time of year (i.e. spawning season, fall season, etc.) unlike a standard survey which samples a wider range of fish species during the summer months using standard methodology (i.e. standard time of year, set sampling stations, taking water clarity readings and oxygen/temperature profiles, etc.) and gears (i.e. lake survey gillnets, trapnets and possibly spring electrofishing for Largemouth Bass). Monson is a small sized (208 acres), shallow (21 feet maximum depth), and moderately productive lake located in Swift County. Monson Lake State Park is located along the east side of the lake. Residential development is limited to 5 homes and 2 recreational vehicles along the south, north and west shore areas. The public access and shore fishing pier are located on the east side in the state park. Usage of Monson State Park and the corresponding public access is generally low compared to nearby Sibley State Park on Lake Andrew. The surrounding watershed is comprised of mostly agricultural row crops with small areas of woodland, grassland, pasture, and wetland areas. The immediate shoreline area consists mostly of undeveloped woodland (hardwood trees) with small to moderate areas of wetlands, row crops, and grassland. Agricultural row crop runoff (via inlets) is the primary source of nutrient pollution into Monson. Nutrient levels were high (total phosphorus=0.063 ppm, Chlorophyll a=53.5 ppb) during 2015 in Monson. There are three small sized inlets (northwest, northeast, and south shores) that flow into Monson. The Monson outlet connects to West Sunburg Lake, which is a shallow, productive and sometimes susceptible winterkill lake. Fish movement is possible between West Sunburg and Monson during high water levels, which has resulted in excellent sunfish growth and good fishing after several mild winters in both lakes. A winterkill probably occurred in the connected West Sunburg Lake in February of 2019. Water levels were above normal during the 2019. Water clarity (secchi reading) was good (12.0 feet) on June 19, 2019. Blue-green algae blooms can be common during the mid to late summer months in Monson Lake. Submergent vegetation is dense and diverse with northern milfoil, various pondweed species (flat-stem, curly-leaf, clasping-leaf, leafy, sago pondweed), coontail, water moss, and filamentous algae present in Monson. Emergent vegetation is also abundant and diverse consisting of various bulrush species, cattail species, duckweed species, burreed, arrowhead, and reed canary grass scattered throughout the bay, shoreline, and island areas. Shoalwater substrates are varied with sand, silt, boulder, gravel, rubble, muck and clay. Northern Pike numbers were moderate in 2019 (4.00 fish/gillnet). The Northern Pike historical average catch rate is 5.03 fish/gillnet for Monson. The 2019 Northern Pike average size was moderate (3.25 pounds and 24.58 inches) from gillnets. The Northern Pike historical average weight is 2.65 pounds from gillnets. There were no fish over 30.00 inches caught in the 2019 survey nets. Northern Pike growth rates were fair. The 2014 and 2015 year classes each comprised 36% of the 2019 Northern Pike gillnet and trapnet catch. Northern Pike possession limit regulations for Monson in the North-central Zone are as follows: anglers can keep 10 Northern Pike, but not more than two pike longer than 26 inches; and all from 22 to 26 inches must be released. 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. Black Crappie were absent in 2019 survey nets. The Black Crappie historical average catch rates are 0.70 fish/trapnet and 1.30 fish/gillnet for Monson. Yellow Perch numbers were low in 2019 (6.50 fish/gillnet). The Yellow Perch historical average catch rate is 11.26 fish/gillnet for Monson Lake. The 2019 Yellow Perch average size was small (0.10 pounds and 6.05 inches) from gillnets. The Yellow Perch historical average weight is 0.22 pounds from gillnets. Bluegill numbers were uncharacteristically low in 2019 (0.44 fish/trapnet). The Bluegill historical average catch rate is 16.65 fish/trapnet for Monson. The 2019 Bluegill average size was small (0.05 pounds and 4.24 inches) from trapnets. The Bluegill historical average weight is 0.24 pounds from trapnets. There were abundant numbers of large Bluegill captured in the previous 2010 survey (2.67 fish/trapnet of 10.00 inches or larger). The largest Bluegill captured was 11.81 inches (about 2 pounds) in the 2010 survey, but only 6.42 inches in the 2019 survey. Bluegill growth rates were above the Spicer Area normal ranges. The 2017 year class comprised 83% of the 2019 Bluegill gillnet and trapnet catch. Walleye numbers were low in 2019 (3.50 fish/gillnet) compared to the Monson historical average catch rate of 4.38 fish/gillnet. The 2019 Walleye average size was large (3.68 pounds and 21.69 inches) from gillnets. The Walleye historical average weight is 2.24 pounds from gillnets. Low numbers of small sized Walleye (0.85 pounds, 11.16 inches) were caught in the 2019 trapnets (1.78 fish/trapnet). Walleye growth rates were good. The 2018 year class comprised 35% of the 2019 Walleye gillnet and trapnet catch. It appears that a 2018 Walleye fry stocking contributed to the fishery. Walleye natural reproduction in Monson is generally infrequent and insignificant based on previous fall and summer surveys. Walleye were recently stocked into Monson during 2012 (54 fingerlings, 3 pounds; 1,252 yearlings, 498 pounds), 2014 (100 fingerlings, 10 pounds; 1,472 yearlings, 339 pounds; 219 adults, 94 pounds), 2016 (504 fingerlings, 21 pounds; 640 yearlings, 320 pounds; 112 adults, 155 pounds) and 2018 (231,135 fry; 28 fingerlings, 2 pounds; 1,441 yearlings, 371 pounds; 29 adults, 39 pounds). Largemouth Bass spring electrofishing survey was not conducted in 2019. A 2015 Largemouth Bass spring electrofishing survey sampled low numbers (17.29 fish/hour). The 2015 Largemouth Bass average size was large (3.07 pounds and 17.33 inches) from spring electrofishing. The 2015 catch rate of preferred size (15.00 inches and larger) Largemouth Bass was high (16.27 fish/hour). Largemouth Bass growth rates were above average in Monson. The 2008 year class comprised 28% of the 2015 Largemouth Bass spring electrofishing catch. Black Bullhead numbers were moderate in 2019 (23.50 fish/gillnet), but below the Monson historical average catch rate of 92.37 fish/gillnet. Black Bullhead abundance in the 2019 trapnets (5.67 fish/trapnet) was also below the historical average (22.04 fish/trapnet). The 2019 Black Bullhead average size was large (1.13 pounds and 12.50 inches) from gillnets. The Black Bullhead historical average weight is 0.86 pounds from gillnets. Current fish management activities on Monson include monitoring the fish population on a periodic basis, protecting aquatic vegetation through the permit process, assisting aquatic plant management and enforcement personnel in educating boaters and monitoring access sites for potential invasive species introductions, participating in local watershed initiatives, and stocking various fish species as warranted. The Monson fishery will be sampled in the 2024 summer for all fish species.

A targeted fall night electrofishing survey was conducted on Monson during September 24, 2018 to evaluate young of year "YOY" (fingerling sized) Walleye numbers due to a fry stocking. Monson is a small sized (208 acres), shallow (21 feet maximum depth), and moderately productive lake located in Swift County. Monson Lake State Park is located along the east side of the lake. Blue-green algae blooms can be common during the mid to late summer months in Monson Lake. Submergent and emergent aquatic vegetation species are abundant within Monson. Shoalwater substrates are varied with sand, silt, boulder, gravel, rubble, muck and clay. There are abundant numbers of Bluegill, Black Crappie, Largemouth Bass and Northern Pike during most years in Monson. Walleye natural reproduction in Monson is generally infrequent and insignificant based on previous surveys and standard analysis. Although past Walleye fingerling/yearling stockings have been successful, a less expensive Walleye fry stocking was attempted in 2018 (231,135 fry). Additional fry stockings will occur in the near future (2020 and 2022), in order to evaluate a change in Walleye stocking strategies for Monson and several other area lakes (Games, Florida, Andrew and Eagle). Walleye fingerling/yearling stockings are contingent the same year if the fry stocking is unsuccessful as documented by fall electrofishing. Various combinations of Walleye fingerlings, yearlings and adults (200-450 pounds per stocking year) have been stocked in recent years including 2014 and 2016. No YOY or Yearling Walleye were captured in the 2018 fall electrofishing survey. Walleye were stocked into Monson shortly after the 2018 fall electrofishing survey (411 pounds total: 28 fingerlings, 1.5 pounds; 1,441 yearlings, 370.5 pounds; 30 adults, 39 pounds) in response to the fry stocking failure. Low (< 8 YOY/hour) or no YOY Walleye numbers were documented due to natural reproduction on Monson during fall electrofishing surveys conducted in 1995, 1997 and 1999. Adult Walleye abundance (6.00 fish/gillnet) was above the 75th quartiles for (25th=3.00, 50th=4.33, 75th=5.00 fish/gillnet) Monson and Lake Class 38 lakes (75th=3.75 fish/gillnet) in the most recent 2015 standard summer gillnet survey. The 2015 Walleye average weight and length were 1.10 pounds and 13.97 inches from gillnets. Large sized Walleye (5.39 pounds average) were caught in the 2015 trapnets (1.22 fish/trapnet). The 2013 and 2006 year classes each comprised 22% of the 2015 Walleye gillnet and trapnet catch. Current fish management activities on Monson include monitoring the fish population on a periodic basis, protecting aquatic vegetation through the permit process, assisting aquatic plant management and enforcement personnel in educating boaters and monitoring access sites for potential invasive species introductions, participating in local watershed initiatives, and stocking various fish species as warranted. The Monson fishery will be sampled in the 2019 summer for all fish species.

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

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

Monson has a maximum depth of 21 feet, per Minnesota DNR data.

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

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