Loon

Loon Lake is a 271 acre lake located nine miles south of Aurora. It is accessed by a ramp on the southwestern side of the east bay of the lake. The 5 lake has a maximum depth of 85 feet and clear water. On August 19, 2020 the lake was thermally stratified with a surface temperature of 72 F and a bottom temperature of 40 F. Oxygen levels were adequate for gamefish to a depth of 26 feet where the temperature was 53 degrees. Lake bottom substrates along the shoreline are mostly gravel and sand with some muck in the bays. Vegetation can be fairly thick in some of the bays. The overall gillnet catch rate for all fish combined was 18.2 fish/net which was below average compared to past surveys on Loon Lake. Yield was 16.9 lbs/net which was also below average. Fish species sampled were yellow perch, bluegill, northern pike, walleye, black crappie, white sucker, hybrid sunfish, largemouth bass, and yellow bullhead. Trap nets caught fish at an overall rate of 27.7 fish/net which was lower than the average of past surveys on Loon Lake. Yield was 8.6 lbs/net which was also below average. Additional species sampled in trap nets that weren't also sampled in gill nets were rock bass and pumpkinseed. Twelve walleye were sampled in gill nets for a catch rate of 2.0 fish/net, which was below average compared to other similar lakes but slightly higher than some of the recent surveys on Loon. Walleye lengths ranged from 10 to 23 inches with an average over 19 inches. This average length was good compared to past surveys on the lake. The average weight was nearly 3 pounds which was very good compared to other similar lakes. Growth rates were excellent with the average walleye measuring 15 inches at four years old. Fish were aged up to 12 years old. Walleye fingerlings are stocked in Loon every other year although there was one walleye of the 12 caught that did not come from a stocked year indicating at least a little natural reproduction. The northern pike gillnet catch rate was 3.8 fish/net which was below average compared to past surveys but better than normal when compared against other similar lakes. Lengths ranged from 13 to nearly 37 inches with an average of just over 19 inches. The black crappie trapnet catch was 2.2 fish/net which was better than average compared to other similar lakes and good compared to past surveys on Loon Lake. Lengths ranged from 5 to 10 inches with an average of 8.5 inches. Sizes were similar to crappies caught in past surveys. The bluegill trapnet catch was 20.7 fish/net which was very good compared to other similar lakes, but slightly below average when compared to past catches on Loon Lake. Sizes ranged from 4 to over 8 inches with an average of 6 inches. Ages ranged from 4 to 10 years old with good representation from all year classes. Growth rates were slow with the average fish taking 8 years to reach 7 inches long. Thirty-three yellow perch were sampled in gill nets for a catch rate of 5.5 fish/net. This was better than average compared to other similar lakes and good for Loon Lake. Lengths were similar to past surveys with a range from 5 to over 9 inches, and an average of nearly 7 inches.

Loon Lake is located approximately 10 miles S of Aurora in the Saint Louis River drainage system. This lake is moderately developed with a variety of dwellings from modern homes to old homesteads with farm land and even an old elementary school. A concrete boat ramp with a dock is located near Road 37 for public access. Fish populations in 2014 were dominated by bluegill and northern pike. Black crappie, walleye, largemouth bass, yellow bullhead, rock bass, pumpkinseed, hybrid sunfish, yellow perch and white sucker were also sampled in relatively low numbers. Bluegill numbers in 2014 (21.2/trap net) were lower than average (37.8/trap net) for this lake. Bluegill sizes averaged 6.3 inches which is slightly larger than the historical average and the largest bluegill sampled was 8.2 inches long. Northern pike numbers in 2014 (3.2/gill net) were lower than average (5.8/gill net) for this lake. Pike sizes averaged 25 inches which is larger than the historical average and the largest pike sampled was a respectable 41 inches long. Black crappie numbers in 2014 (3.4/trap net) were higher than average (1.2/trap net) for this lake. Crappie sizes averaged 8.8 inches which is larger than the historical average and the largest crappie sampled was 11.2 inches long. Walleye numbers in 2014 (1.8/gill net) were similar to the average (2.0/gill net) for this lake. Walleye sizes averaged 17.4 inches long which is larger than the historical average and the largest walleye sampled was 27.8 inches long. Walleye fingerlings are stocked on even numbered years.

Loon Lake is in Ecological Lake Class 5, which consists of 64 lakes in northeast Minnesota that have shorelines with steep drop-offs and clear, soft (low mineral content) water. Loon Lake is deeper and has higher total alkalinity than most of the lakes in Lake Class 5. Loon Lake was thermally stratified on 07/13/2009 with a surface temperature of 68 �F and a bottom temperature of 41 �F. Adequate oxygen for fish (2 ppm) was retained to a depth of 40 feet, where the temperature was 46.4 �F. The ditched inlet to Loon Lake originates in Kumpala Lake. The outlet is to Mud Hen Lake: shallow water and downed trees may limit fish movement in the outlet. Bottom substrates along the shoreline of Loon Lake are 70% sand, 14% gravel, 10% muck, and 6% rubble. Aquatic plants are abundant in a fringe along the shoreline and grow to a depth of 10 feet. Sedges, rushes, and floating leaf pondweed are the most common plants. The 2009 fish population assessment consisted of 6 standard gillnet sets and 9 trapnet sets. Ten previous fisheries investigations, dating back to 1960, used 3-6 gillnets. Seven previous investigations used 4-10 trapnets. Shoreline seining was done during the 1960 and 1985 investigations. Fish populations in 2009 were dominated by bluegill sunfish, yellow perch, and northern pike. Other fish species caught in 2009 included walleye, black crappie, largemouth bass, white sucker, pumpkinseed sunfish, hybrid sunfish, brown bullhead, black bullhead, yellow bullhead, and rock bass. No bluegills were captured in the initial investigation in 1960; they were first observed in the 1965 investigation and their abundance began to increase in 1978. Bluegill numbers in 2009 (49.2/trapnet) were above average for Lake Class 5 and higher than the median catch rate (37.8/trapnet) for all investigations on Loon Lake. Bluegill size averaged 6.1 inches (0.18 lb) in the trapnets, which was near the median for this lake class. The largest bluegill was 8.0 inches. Bluegill ageing revealed six year classes in the 2009 trapnet catch and the majority were from the 2002 and 2003 year classes. Bluegill growth was slower than normal by area standards. Northern pike numbers in 2009 (5.5/gillnet) were normal for Lake Class 5 and similar to the median catch rate (5.8/gillnet) for all investigations on this lake. Pike sizes in 2009 averaged 21.2 inches (2.4 lbs) in the gillnets, which was normal for this lake class. The largest pike was 30 inches. Northern pike from 8 year classes were represented in the 2009 gillnet catch. Growth was normal by area standards. Walleye numbers in 2009 (0.7/gillnet) were below average for this lake class and lower than the median (1.0/gillnet) for all Loon Lake assessments. The walleye catch rate peaked in 1985 (9.7/gillnet) and 1988 (9.0/gillnet), but has since declined and remained at a low level in recent investigations. The average size of gillnet captured walleye in 2009 was 15.1 inches (2.1 lbs), which is normal for this lake class. Ageing revealed three year classes in the 2009 catch, all fingerling stocked years. The yellow perch catch rate in 2009 was 7.5/gillnet; higher than the median (3.4/gillnet) for all investigations on this lake and normal for this lake class. The 2009 catch rate was the highest it has been since the initial survey in 1960 (10.2/gillnet). Perch size averaged 6.1 inches in the 2009 gillnets, similar to the average length (6.8 inches) for all Loon Lake assessments. The largest perch in 2009 was 8.8 inches. Sampled perch were represented by 4 age classes and growth was slower than normal by area standards. Black crappie numbers have varied widely in previous investigations. The 2009 trapnet catch rate of 1.1/trapnet was at the median for all investigations and was in the second for Lake Class 5. The 2009 catch rate of 4.7/gillnet was higher than the median (1.3/gillnet) for all investigations and above average for Lake Class 5. Average crappie size in 2009 was 8.2 inches. Crappies up to 12.2 inches have been captured in previous iinvestigations. Largemouth bass were caught in low numbers in gillnets and trapnets in 2009, similar to recent iinvestigations. Bass are not sampled effectively using standard gillnets and trapnets, and largemouth bass numbers are likely higher in Loon Lake than the gillnet and trapnet numbers suggest. Most of the game fish captured in 2009 were infected with neascus (black spot). Most of the yellow perch and one yellow bullhead were infected with yellow grub. Neascus and yellow grub are common parasites that are native to the area. They cannot infect humans and are killed at temperatures used to cook fish.

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

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

Loon has a maximum depth of 85 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Loon is from 2020.

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