Loon

Loon Lake is a large, 1,096-acre lake within Cook County and has a maximum depth of 202 ft. There is a small concrete boat access and two remote campsites located on the northwest side of the lake, just off the Gunflint Trail. Loon Lake is primarily managed for lake trout and smallmouth bass. In 2024, a standard survey was conducted using gillnets and trap nets to assess the current fish community. Lake trout are the primary management species in Loon Lake and catches in the 2024 survey met management goals. Lake trout catch rates were just below the long-term average for the lake but have been slowly declining since 1993. Lake trout lengths ranged from 11.0 to 32.8 inches, with an average size of 18.5 inches. Quality and preferred sizes of lake trout were present in Loon Lake, with 29% of the fish exceeding 20.0 inches and 12% exceeding 26.0 inches. Lake trout growth was slow, as it took fish 12 years to reach 16.0 inches on average. Lake trout can grow big in Loon Lake due to the excellent forage species, cisco, present within the lake. Anglers looking to target lake trout on Loon Lake should expect to catch fair numbers of quality sized fish with the opportunity to catch trophy sized individuals. Smallmouth bass are the secondary management species within Loon Lake and catches in the 2024 survey met management goals. Catch rates in trap nets were average for Loon Lake, but very high in gill nets. This is likely due to an expansion of smallmouth bass into deeper waters where gill nets are typically set. Smallmouth bass lengths ranged from 5.3 to 14.7 inches and were relatively small on average. Only one smallmouth bass was larger than 14.0 inches from the survey. Anglers looking to target smallmouth bass on Loon Lake should expect to catch a relatively high number of small fish rather than large individuals. Northern pike catch rates have been stable since 2007 but were observed at relatively low numbers during the 2024 survey. Northern pike ranged from 21.7 to 33.1 inches and averaged 26.5 inches. Loon Lake has been known to produce some larger sized northern pike since cisco are present and provide a high-quality forage. Walleye catch rates were below the long-term average but have always been low in Loon Lake. Walleye lengths ranged from 9.9 to 17.4 inches and averaged 14.1 inches. Walleye growth was relatively fast in Loon Lake compared to other Grand Marais area lakes, taking only three years to reach 16.0 inches on average. Rock bass abundance has continued to increase in Loon Lake and catch rates from the 2024 survey were the highest on record. Bluegill were also caught during the survey, but catches were average and most likely not of any interests to anglers. Cisco are an important forage species for lake trout and northern pike in Loon Lake. Catch rates have been good and relatively stable since 1999. Cisco lengths ranged from 8.5 to 13.0 inches and averaged 11.4 inches. Larger sized cisco may be an additional species ice anglers may be interested in targeting on Loon Lake.

Loon Lake is part of the headwaters for the Rainy River system, discharging to that system via Crab and Gunflint Lakes. It is a classic deep Canadian Shield lake, managed primarily for Lake Trout and Smallmouth Bass. This was the second of two standard surveys scheduled in the 2013 lake management plan to monitor Lake Trout and Smallmouth Bass, and to complete the evaluation of the Northern Pike special regulation on this lake. The first survey was done as scheduled in 2015. Based on those surveys, the management plan for Loon Lake will be revised in March 2021. Comments on the management of the lake will be welcome as we work on that plan. Fair numbers of Lake Trout were present in 2019, including some fish up to 30 inches in length. The combined Lake Trout catch in deep and shallow gill net sets (1.67 fish/set) exceeded the long range goal from the 2013 plan (1.0 fish/set), and was similar to catches seen in this lake since 1970. All of the Lake Trout collected in 2019 had been produced naturally. Seven year classes contributed to the catch, including fish as old as 14 years. None of the year classes sampled appeared to have been exceptionally strong, but reproduction had apparently been occurring on a fairly consistent basis. Growth of young Lake Trout had been slow; across all age classes fish reached a mean length of just 8.4 inches at the end of their fourth year, compared to an area average of 12.1 inches. Slow growth of young Lake Trout was likely due to intense competition from Cisco for invertebrate forage. Larger Lake Trout would have benefited from the excellent Cisco forage base in this lake. As has often been the case, sampling in 2019 yielded mixed messages concerning Smallmouth Bass abundance. The catch in trap nets was high, while the gill net catch was low. It was clear, however, that bass in this lake tended to be small, with just a few exceeding 11 inches in length. In 2019 Smallmouth Bass appeared to have been fairly abundant in nearshore areas; the trap net catch exceeded the normal range for this type of lake, and was the second highest ever seen in Loon Lake. Fewer fish were seen off shore, and the gill net catch was quite low for a lake of this class. Most of the Smallmouth Bass taken in 2019 were under 10 inches in length, but that was not unusual for this lake. Smallmouth Bass growth had been slow; fish reached a mean length of just 5.4 inches at the end of their third year, compared to an area average of 7.0 inches. It took about six years for most fish to reach 10 inches in length. As has usually been the case, Northern Pike in Loon Lake were low in numbers but large in size in 2019. The combined Northern Pike catch in deep and shallow gill net sets (0.42 fish/set) was within the normal range for the lake class (0.27-1.02 fish/set), and was similar to most past catches in this lake. Although based on only five fish, the mean weight for fish taken in gill nets was above the normal range for the lake class. Northern Pike as old as seven years were collected and growth of young fish had been somewhat faster than average for the area. The objective of the 2003 Northern Pike special regulation, to prevent a decline in relative size distribution (percent of fish over 24 inches in length) while maintaining historic proportions of 30-inch or larger fish in gill net catches, appeared to have been met by 2019. However, improvements in the Northern Pike population in Gunflint Lake (the exprimental control) appeared to have been at least as great, suggesting the the population in Loon Lake might have done well for reasons not related to the regulation. Fishing pressure targeting Northern Pike had been very low on Loon and Gunflint Lakes; the goal of the regulation was to maintain the quality of the fishery against possible future increases in fishing pressure on those lakes. We do not know whether fishing pressure changed in either lake during the regulation period, since no creel survey data are available. Results of post-regulation surveys in Loon Lake suggested the Northern Pike size distribution had remained the same or improved slightly since 2003, and that numbers of fish taken (in surveys) larger than 30 inches did not decline. However, in Gunflint Lake similar results were observed, despite a more liberal season (continuous) and more liberal size and bag limits. Based on survey results obtained through 2015, in the fall of 2018 we recommended the Northern Pike regulation on Loon Lake be dropped. Public input indicated no interest in retaining the regulation, so on March 1 2020, Northern Pike regulations on Loon Lake reverted to the standard for the Northeast Zone - a bag limit of two fish, with a 30-40-inch protected slot, with one fish over 40 inches allowed in possession. Walleye numbers in Loon Lake have always been low, and the 2019 gill net catch of just a single fish was not unusual for this lake. Walleye recruitment in this lake has been low and sporadic, despite the presence of excellent spawning habitat in many locations. Cisco remained abundant in Loon Lake in 2019. The combined catch in deep and shallow gill net sets (8.83 fish/set) was at or above the average for the lake class (7.65 fish/set), and was similar to catches seen in this lake since 1987. Almost all Cisco taken in 2019 were heavily infested with Triaenophorus, a tapeworm that forms large cysts in muscle tissue. While Cisco still provided excellent forage for Lake Trout and Northern Pike, their value for human consumption was very limited. Loon Lake is one of very few lakes in the area that support significant panfish populations. Bluegill and Rock Bass trap net catches in 2019 were the highest ever seen in this lake; both exceeded normal ranges for the lake class. Most fish of both species were small, but there were enough over six inches in length to have driven some angler interest. Yellow Perch were never abundant in Loon Lake, but since the early 1980s, when Rock Bass become established, they have all but disappeared. White Sucker gill net catches have also declined over the same period.

Loon Lake is a classic deep Canadian Shield lake, managed primarily for Lake Trout and Smallmouth Bass. This was the first of two standard surveys scheduled in the 2013 lake management plan to monitor Lake Trout and Smallmouth Bass, and to continue the evaluation of the Northern Pike special regulation on this lake. Northern Pike in Loon Lake have been covered by a 30-inch minimum size limit since 2003. Gunflint Lake was the control lake for that evaluation. Only fair numbers of Lake Trout were found in the 2015 survey, and most were small. The combined Lake Trout catch in deep and shallow gill net sets (0.92 fish/set) fell just below the long range goal from the 2013 plan (1.0 fish/set), and was the lowest seen in this lake since 1970. All of the Lake Trout collected in 2015 had been produced naturally. Fish as old as 13 years were taken (although most were younger), and six year classes contributed to the catch. None of the year classes sampled appeared to have been strong, but some reproduction had apparently been occurring on a fairly consistent basis. Growth of young Lake Trout had been slow; fish reached an average length of just 7.8 inches at the end of their fourth year, compared to an area average of 12.1 inches. Slow growth was likely due to intense competition from Cisco for invertebrate forage. Smallmouth Bass appeared to have been fairly abundant in near-shore areas in 2015, but most were small. Few fish were found in off-shore areas, and only two fish larger than 11 inches were captured. Similar results (large numbers of small fish) have been seen in most past surveys of this lake. As has usually been the case in Loon Lake, the Northern Pike gill net catch was low, but included several larger fish. Northern Pike benefit from the excellent forage provided by Cisco in this lake, and from cool-water refuge areas the lake provides. Survey data suggested the objectives of the 2003 Northern Pike regulation had been met. However, it was impossible to say whether the regulation was the cause because the Northern Pike population in the unregulated control lake (Gunflint) also improved over the same period. Loon Lake has consistently supported small numbers of Walleye, and often produces some large fish of that species. That was again the case in 2015. The combined Walleye catch in deep and shallow gill net sets (0.42 fish/set) was below the lower edge of the normal range for this type of lake (0.58 fish/set), while the mean weight for Walleye taken in those nets (4.48 lb/fish) was well above normal. Walleye as old as 18 years were collected, but only four year classes contributed to the catch. Walleye reproduction in this lake has been low and sporadic, despite the presence of excellent spawning habitat in many locations. Cisco remained abundant in Loon Lake in 2015. The combined catch in deep and shallow gill net sets (9.08 fish/set) was high for a lake of this type, but was similar to catches seen in this lake since 1987. Cisco in Loon Lake are heavily infested with the tapeworm Trienophorus, and so are not desirable for human consumption. Loon Lake is one of very few lakes in the Grand Marais area that support significant panfish populations. The 2015 Bluegill trap-net catch was well above average for this type of lake (or for any lake in this area), and although most were small, a few exceeded six inches in length. Rock Bass were also abundant, and few may have been large enough to have been of interest to anglers.

Based on Minnesota DNR survey data, anglers target Northern Pike, Walleye, Lake Trout, Rock Bass, and Yellow Perch 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 202 feet, per Minnesota DNR data.

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

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.