Boys

Boys Lake is a small, 24-acre lake with a maximum depth of 13.0 feet located 10 miles northeast of Grand Marais. Access to the lake is considered moderate, with a short 0.25-mile portage from Mink Lake. Water temperatures and dissolved oxygen concentrations in Boys Lake have supported conditions that are suitable for stocked trout during the summertime. Boys Lake is currently managed for brook trout and is stocked with 2,000 fingerlings during the fall of odd-numbered years. The long-range goal for brook trout is to maintain a minimum gillnet catch of 1.5 fish/net with fish greater than 12.0 inches present. In 2025, a standard survey was conducted on Boys Lake to monitor the fishery and determine if brook trout catches were meeting management objectives. The 2025 catch rate from gillnets was average for the lake at 8.0 fish/net and was above the management goal for the lake. Brook trout lengths ranged from 6.6 to 15.4 inches, with an average length of 11.0 inches. Additionally, nearly half of the catch was greater than 12.0 inches and met the size goal for the lake, providing anglers with the opportunity to catch harvestable sized brook trout. Age analysis found two year classes present (age two and four) from the 2023 and 2021 stocking events, and show that brook trout are able to survive multiple years in Boys Lake. Brook trout growth in Boys Lake was below average, taking fish four years to reach 13.7 inches on average. Habitats were marginal for brook trout in late summer, with only a small portion of the water column that was cold enough to support brook trout; however, oxygen was not limiting. Anglers looking to fish Boys Lake can expect moderate catch rates of brook trout within a short drive from Grand Marais. Other species caught during the survey included splake and yellow perch. The splake catch rate was low, but sizes were desired by most anglers, with an average size of 14.5 inches. Yellow perch catches were also low; however, both fish caught were mature and may indicate a reproducing population within the lake. Continued increases in the yellow perch population may cause adverse effects on the stocked trout fishery in Boys Lake. Both splake and yellow perch likely migrated into Boys Lake from downstream Mink Lake and indicate a need to stop fish passage between these two systems. Minnesota Lakes within Cook County continue to be susceptible to aquatic invasive species introductions. Invasive species have the potential to significantly alter fish communities and overall lake health. Anglers should clean watercraft and fishing gear, drain all water, and dispose of unused bait in the trash to prevent accidental introductions.

Boys Lake has been managed for stream trout since at least 1950, and was last rehabilitated in the fall of 2014. The management goal for this lake, established in the 2015 lake management plan revision, is to maintain a Brook Trout population with a minimum gill net catch of 1.5 fish/set, with some fish over 12 inches in length present. This was the first survey of this lake to be done since it was rehabilitated. It was also the first of two surveys scheduled in the 2015 plan to determine whether Brook Trout performance was limited by marginal summer water temperatures, and to identify any Brook Trout natural reproduction. At the time the lake was rehabilitated, it supported a natural Brook Trout population. Brook Trout numbers were apparently very high in the fall of 2018, and many fish over 12 inches in length (up to 17.4 inches) were present. The gill net catch in this survey exceeded the plan goal by a wide margin, and was well above the normal range for a fall survey of a stream trout lake in this area (1.3-14.0 fish/set). All three stocked year classes were represented in the catch. Growth of older Brook Trout had been somewhat slower than average, with fish reaching a mean length of 11.3 inches by the end of their third year, compared to an area mean of 12.7 inches. The Brook Trout catch included two fish that appeared to have been two-year-olds. If the aging was correct, those fish were either produced naturally or they were Splake that had moved into the lake from Mink Lake and were misidentified as Brook Trout. The 2018 catch included at least two Splake that would have been stocked in Mink Lake. It is possible that more were included in the Brook Trout catch, because the crew was not expecting to see Splake, and may have identified some as Brook Trout before they realized Splake were present. Splake movement into Boys Lake has been observed in the past. No undesirable fish species were observed in the catch. Boys Lake was rehabilitated to remove a dense Yellow Perch population, and it appeared that effort had been successful. However, the rehabilitation should also have eliminated minnows from the lake, yet several species were collected in minnow trap set during this survey. Trout in this lake depend on surface waters remaining cool through the summer, since the lake is shallow and lacks any deeper waters capable of providing cold-water habitat. A temperature-oxygen profile measured on 23 August found conditions suitable for Brook Trout (water temperature 5 ppm) at depths of two to eight feet, with no deeper waters found. Surface water temperatures in the area had already been cooling for some time prior to 23 August, so conditions may have been more stressful earlier in the summer.

This assessment was done in cooperation with Cook County water planning staff, as part of a water quality study on Mink, Kimball, and Boys Lakes. It was also done to monitor performance of stocked trout, and to determine whether yellow perch or rock bass had become established in Boys Lake. Boys Lake lies at the head of the Kimball Creek watershed,above Mink and Kimball Lakes. Yellow perch were reported by anglers in Mink and Kimball Lakes in 2008, and were found in both lakes in fairly high numbers in assessments done in late summer 2009. In addition rock bass were found in Kimball Lake in 2009. By 2013, both species were abundant in both lakes. Yellow perch were apparently abundant in Boys Lake in 2013. The gill net catch was above average for the lake class, and many small yellow perch were taken in minnow traps. Yellow perch may have provided some angling opportunities, since the gill net catch included fish as large as 12 inches in length. No rainbow trout from any recent stockings were collected in 2013. There should have been fair numbers of fish from the 2011 stocking present, but none were taken. It appears that all stockings of rainbow trout in this lake since 2007 failed. Although none have been stocked in this lake since 2006, the 2013 assessment, like the 2009 assessment, captured fairly high numbers of brook trout. The 2013 gill net catch exceeded the median (6.00 fish/set) for fall assessments of stream trout lakes in this area. Four year classes were represented in the catch, and all must have been naturally produced. Growth appeared to have been about average for the area, despite the presence of large numbers of yellow perch. Two-year-old brook trout reached an average length of 9.4 inches by the end of their second year. Brook trout in Boys Lake must have been produced in or upstream of that lake, or have migrated to the lake from Kimball Creek. No brook trout have been stocked in any lakes connected to, or near, Boys Lake since 2006. There is a resident brook trout population in Kimball Creek, in areas below Kimball Lake and between Mink and Kimball Lakes, but brook trout have rarely been seen in Kimball or Mink Lakes (unless stocked). Regular stocking of Boys Lake with brook trout would have masked any evidence for prior movement of brook trout from Kimball Creek into the lake; however, if they've rarely been seen in Mink Lake, it seems unlikely that much higher numbers of brook trout would have moved all the way upstream into Boys Lake. Natural reproduction, in Boys Lake or in one of its small inlets, may have occurred. There are known to be some springs in the north end of Boys Lake. Three inlets were identified in the 1974 survey; two were spring fed and one of those had some gravel present. Inlets to Boys Lake were examined in 2013, and temperature monitors were placed in the only two flowing inlets found (both in the NW corner of the lake. Flows in both inlets were low, but cool water temperatures in one suggested it was probably fed by springs or cool seeps. However, neither inlet seemed to provide any spawning habitat for brook trout (no gravel). A temperature-oxygen profile obtained in Boys Lake on 27 August 2013 found conditions at the surface that may have been lethal for brook trout, while conditions at all depths would have been stressfully warm. Temperature monitors were deployed in Boys Lake, at depths of 1.7 and 6.6 feet above the bottom, from February 2013 through October 2013. Water temperatures that would have been stressful for brook trout (over 68 F) were recorded by the deeper of the two monitors during two prolonged periods: over the first two-thirds of July and the last half of August. Although temperatures were warmer near the surface (6.6 feet above the bottom), and periods of stressful conditions slightly longer, periods of potentially lethal temperatures were brief. Conditions in the lake appeared to have improved rapidly after 27 August. Relatively high brook trout catches seen in this September assessment indicated that brook trout were able to survive the warm lake conditions measured in 2013. Boys Lake is scheduled to be rehabilitated for stream trout management in the fall of 2014, with the goal of eliminating yellow perch. All fish present at that time would be killed, and the lake would be restocked beginning in the spring or fall of 2015.

Based on Minnesota DNR survey data, anglers target Brook Trout, Yellow Perch, and Splake in Boys. See the full species list above for catch rates, size structure, and quality scores.

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

Boys has a maximum depth of 13 feet and a mean depth of 5.4 feet, per Minnesota DNR data.

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

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