Birch

Birch Lake is a 236-acre lake located 34 miles north of Grand Marais and public access is through a carry-in access along the south shore. Rainbow trout are the primary management species with yearlings stocked every year since 2016. Brook trout were last stocked in 2015 and were not captured in the 2023 survey. In addition, there is a small natural population of lake trout that continues to persist despite limited habitat. The 2023 standard survey of Birch Lake was conducted to evaluate survival and growth of stocked rainbow trout. Rainbow trout catches in the 2023 survey gill nets were comparable to the last two surveys (3.83 fish/net) and were slightly above average for similar lakes in the area. Rainbow trout captured ranged from 10.4 - 18.6 inches with most of the fish being about 12 inches long. There were slightly less larger fish in the population than in previous surveys. Aging results indicated that fish from 3 year classes were present in the lake with the oldest being 3 years old. Growth rates for rainbow trout were good. Birch Lake continues to provide good angling opportunities for rainbow trout. Despite marginal temperature-oxygen conditions that provide limited habitat for lake trout in most years, the lake trout population has continued to persist in Birch Lake. The lake trout catch was very low but similar to catches seen in this lake since 2007. The one lake trout taken in the survey was 12 years old and 21.7 inches. Naturally reproducing lake trout populations are unique in Minnesota lakes, anglers targeting lake trout should consider catch and release practices with safe handling procedures. Catches in 0.25-in-mesh trap nets indicated there has been no recovery of the nearshore fish community, which collapsed after smallmouth bass became established in this lake in the mid 2000s. As has been the case in most recent surveys, no minnows were found. There was one small (4.7 inch) smallmouth bass collected in the 2023 survey which is the fewest seen in surveys since they were detected in 2004. Smallmouth bass are likely not abundant enough to provide good angling opportunities. Cook County, Minnesota lakes 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.

This was the first of three standard surveys scheduled in the 2014 lake management plan to evaluate a change in Rainbow Trout stocking quota and frequency, slated to begin in 2016. It was also the final survey done to evaluate Brook Trout yearling stocking in this lake, which was discontinued after 2015. Beginning in 2016, Rainbow Trout yearlings will be stocked annually, rather than every-other year. Rainbow Trout were fairly abundant in the fall of 2015, and although no large fish were taken, their mean length (about 16 inches) was high enough to drive some high-quality fishing. The combined Rainbow Trout catch in deep and shallow gill net sets (3.0 fish/set) met the long range goal from the 2014 plan (a minimum of 2.0 fish/set). The mean weight for Rainbow Trout collected in 2015 equaled the long range goal from the 2014 plan (1.4 lb/fish). The catch consisted entirely of two-year-old fish from the 2014 yearling stocking. Survival of fish to older ages seemed to have been low, but that was not surprising in this popular and accessible lake. The shift to annual stocking should result in fish up to three years of age being more consistently present in this lake. Rainbow Trout growth appeared to have been somewhat faster than average; fish reached a mean length of 12.5 inches by the end of their second year, compared to an area average of 11.6 inches. The relatively high number of fish surviving to almost three years of age, and the good growth rates exhibited by those fish, suggested that this lake could be managed successfully for Rainbow Trout despite the presence of Smallmouth Bass. Despite regular stocking, few Brook Trout were found in 2015. The combined Brook Trout catch in deep and shallow gill net sets (0.3 fish/set) was low, falling below the normal range (1.25 - 14.00 fish/set) for gill net catches in fall surveys of stream trout lakes in the Grand Marais area. Of the three Brook Trout collected, two were probably survivors of the 2015 yearling stocking. The third may have been produced naturally; Brook Trout (and Splake) not accounted for by any stocking have been taken in small numbers in this lake in the past. It appeared that alternate-year yearling stocking in this lake since 2009 had not produced a significant Brook Trout population, although a few have survived. Brook Trout may compete more directly with Smallmouth Bass for available forage, and their smaller size at stocking may have left them more vulnerable to predation. Despite marginal temperature-oxygen conditions that provide little or no suitable habitat in many years, a small natural Lake Trout population has persisted in Birch Lake. The Lake Trout catch was similar to catches seen in this lake since Lake Trout stocking was discontinued, but was low compared to other area Lake Trout lakes. Both of the Lake Trout taken in this survey were small, young fish that would have been produced naturally. Catches in 0.25-in-mesh trap nets indicated there has been no recovery of the nearshore fish community, which collapsed after Smallmouth Bass became established in this lake. As has been the case in most recent surveys, no minnows were found and it appeared that Smallmouth Bass dominated nearshore areas, at least at this time of year.

Birch Lake is currently managed for rainbow and brook trout. The long range goal (from the 2008 management plan) for rainbow trout is to maintain a rainbow trout population with a minimum gill net catch of 1.0 fish/set, and a minimum mean weight of 1.4 lb/fish. The long range goal for brook trout is a population with a minimum gill net catch of 3.0 fish/set and a minimum mean weight of 0.75 lb/fish. This was the second of two assessments scheduled in the 2008 plan to determine growth and survival of stocked rainbow and brook trout. The current management plan for Birch Lake will be reviewed and revised in March 2014. Assessments of Birch Lake use a combination of deep and shallow gill net sets. Deep sets target coldwater species, while shallow sets target warm and cool-water species. In DNR Lakefinder reports, catches in those nets have been combined. In addition, 0.25-in-mesh trap nets were used in this assessment to monitor the nearshore fish community. Catches for those nets are not included in Lakefinder reports. The combined rainbow trout catch in deep and shallow gill net sets (4.78 fish/set) easily met the current long range goal for the species, and fell within the normal range (1.00-6.50 fish/set) for fall assessments of stream trout lakes in this area. The mean weight for rainbow trout taken in gill nets (1.14 lb/fish) fell short of the long range goal, but exceeded the normal range (0.53-1.13 lb/fish) for fall catches in area stream trout lakes. The rainbow trout catch was dominated by one-year-old fish from the 2012 yearling stocking, although a small number of three-year-old fish from the 2010 stocking were also present. Rainbow trout growth over the summer of 2012 had apparently been good. Fish were stocked in the early spring at an average weight of 0.33 lb/fish, while the mean weight for one-year-old fish taken in September was 0.92 lb/fish. Growth for the three-year-old rainbow trout taken in this assessment had been fast; they reached an average length of 18.1 inches at the end of their third year, compared to an area average of 14.3 inches. Short-term growth and survival of stocked rainbow trout had been relatively high, despite the presence of smallmouth bass. Rainbow trout are well adapted to thrive on an invertebrate forage base. It is possible that smallmouth bass, by decimating minnow populations in this lake, reduced competition faced by rainbow trout for invertebrate forage. The combined brook trout catch in deep and shallow gill net sets (0.44 fish/set) fell well short of the goal set for the species, and was below the normal range for fall assessments of stream trout lakes in this area (1.50-14.00 fish/set). The size goal was met, since the catch consisted entirely of two- and three-year-old fish from stocking done in 2011 and 2010. Brook trout growth had been somewhat slower than average. Fished reached an average length of 9.1 inches by the end of their second year, compared to an area average of 9.4 inches. Smallmouth bass have probably had an adverse effect on brook trout survival and growth. Although brook trout yearlings (instead of fingerlings) have been stocked to reduce direct predation from bass, they have not been as large as the rainbow trout yearlings stocked, and some predation may have occurred. Brook trout growth has generally been better when they have had access to a minnow forage base. Loss of minnow populations in this lake probably reduced the potential for good brook trout growth. The smallmouth bass catch in shallow gill net sets was within the normal range (0.50-1.50 fish/set) for that gear. Only two year classes were represented in the combined assessment catch (two five-year-old fish in gill nets, five one-year-old fish in 0.25-in trap nets), suggesting that smallmouth bass reproductive success or recruitment might be sporadic in this lake. Despite the lack of suitable habitat, there may still be a few lake trout remaining in Birch Lake. One large fish was taken in this assessment. The temperature-oxygen profile found no portion of the water column with conditions suitable for lake trout (temperature 5 ppm), but conditions that may have been at least survivable were found at depths of 27 to 30 ft. No new undesirable fish species were found in 2012. The white sucker gill net catch was relatively low compared to catches seen in this lake since 1994, and fell within the normal range for shallow sets in stratified assessments in this area (1.23-5.00 fish/set). For the third assessment in a row, no minnows of any kind were taken in 0.25-in-mesh trap nets. Minnows were abundant in Birch Lake prior to the appearance of smallmouth bass.

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

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

Birch has a maximum depth of 69 feet and a mean depth of 26 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Birch is from 2023.

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