Aspen

Aspen Lake is part of a cluster of small-to-medium sized, easily accessed lakes about 30 road miles from Grand Marais. It supports a simple fish community; among the major species present, only northern pike, yellow perch, and white sucker were native. Walleye were introduced in the 1930s, while smallmouth bass and black crappie were first taken in survey nets in 1977. The latest (2014) lake management plan (LMP) for this lake established walleye and northern pike as primary and secondary management species, with black crappie providing a minor fishery. Management goals from the plan were to maintain a walleye population with a minimum gill net catch of 4.0 fish/net, with some fish over 20 inches, a self-sustained northern pike population with a minimum gill net catch of 1.2 fish/net, and a self-sustained black crappie population with a minimum catch of 0.70 fish/0.75-in trap net set, with those fish maintaining a mean weight of at least 0.75 lb/fish. This was to have been the second of three standard surveys scheduled to evaluate an increase in walleye stocking that began in 2015. The first, in 2016, could not be completed due to a lack of staff and funding. Increased walleye fry stocking (from 90,000/stocking to 150,000/stocking) began in 2015, and any results of that increase would probably not have been fully realized by 2020. Nevertheless, early results were not promising. The walleye gill net catch in this survey was the lowest ever seen in Aspen Lake, falling well short of the catch goal for this lake. Six year classes contributed to the catch, including two (2018 and 2017) that had been naturally produced. Year classes produced in years when stocking had been done (2012, 2015, 2016, and 2019) accounted for 79% of the total walleye catch; however, it was likely that some of those fish had also been produced naturally. Growth of young walleye had been about average for this area. Fish reached a mean length of 12.9 inches at the end of their fourth year. The 2020 northern pike gill net catch was also low for this lake historically (the second lowest seen in this lake), and was short of the 2014 goal. However, those results could have been misleading, since a fairly high number of northern pike were taken in trap nets in 2020. The trap net catch was the second highest ever seen in Aspen Lake. Northern pike were probably spending more time in the shallows at the time this survey was done, so were less likely to be taken in gill nets set off-shore, and more likely to turn up in shoreline trap nets. Although most of the northern pike caught were under 22 inches in length, there were a few over 24 inches to provide some higher-quality catches. Black crappie have been rare in the Grand Marais area, and although they have been consistently sampled in Aspen Lake, their numbers have never been high. Results of the 2020 survey were typical for this lake. A few crappie were taken in trap net sets, and although the trap net catch fell below the 2014 catch goal, the size goal in that plan was met. Black crappie as large as 13 inches were taken in trap nets. Smallmouth bass support a secondary fishery in Aspen Lake, and have been targeted by a few anglers there. Fishing for bass can be quite good for those targeting the species. Gill and trap net catches are not good indicators of smallmouth bass abundance, and often provide contradictory information on sizes available. Smallmouth bass taken in both gears in 2020 ranged in length from 6.4 to 18.7 inches. Yellow perch have been the primary forage species supporting walleye and northern pike in this lake. The 2020 gill net catch was fairly low for a lake of this type, but was typical of lower catches seen in this lake since 1983. Yellow perch would have provided some angling opportunity in 2020; fish taken in gill nets and trap nets ranged in length from 5.4 to 11.5 inches.

Aspen Lake is currently managed for walleye and northern pike. The long range goal for walleye is to maintain a minimum gill net catch of 4.0 fish/set, with some fish over 20 inches. The goal for northern pike is a minimum gill net catch of 1.2 fish/set (with no size goal). One of the objectives of the current (2006) lake management plan was to develop a long range goal for black crappie in this lake. The other was to determine whether continued stocking of walleye was needed. This was the second of two assessments scheduled to help meet those objectives. The 2012 walleye gill net catch did not meet the long range goal for Aspen Lake; however, it was similar to catches observed in this lake since 1989. The 2012 catch may have been influenced by unusually low oxygen levels in deeper waters that may have reduced the walleye catch in some of the deeper net sets. The walleye size goal was met in 2012 with the capture of one 22.6-inch fish. Several year classes contributed to the walleye catch. Year classes supplemented by stocking accounted for 14 of the 22 walleye taken in gill nets or trap nets, but stocked and unstocked year classes were about equally strong. The stocked 2007 year class contributed the most fish to the catch (nine), but second and third-highest contributions came from unstocked year classes in 2010 and 2006. Walleye growth rates were average or better; five-year-old fish in Aspen Lake reached a mean length of 15.1 inches by the end of their fifth year, compared to an average of 14.4 inches in similar lakes in this area. Walleye stocking probably contributes to the walleye catch in Aspen Lake, although the population is probably not dependent on stocking. There is some evidence to suggest that higher gill net catches were achieved when stocking rates in this lake were higher. Continued stocking, and perhaps an increase in stocking rate, may be needed to produce a walleye population consistently meeting the current long range goal. The 2012 northern pike gill net catch easily met the long range goal for the species. Northern pike gill net catches in this lake have risen fairly steadily since 1989, and the 2012 catch approached the upper end of the normal range for the lake class. Size of northern pike collected has been more stable, ranging from 1.5 to 2.5 lb/fish since 1992. The mean weight for northern pike collected in 2012 fell within that range, and was average for a lake of this type. Four year classes contributed to the 2012 catch, and the 2010 year class was apparently fairly strong. Despite the lack of a strong yellow perch forage base, northern pike growth had been somewhat faster than average. Three-year-old fish reached an average length of 19.8 inches by the end of their third year, compared to an average of 18.1 inches in similar lakes in the Grand Marais area. The 2012 yellow perch gill net catch was low for a lake of this type, and low for Aspen Lake historically. No yellow perch were taken in 0.75-in-mesh trap nets. A few small yellow perch were taken in 0.25-in-mesh trap nets, and that gear also collected young-of-year (YOY) yellow perch. The YOY catch (20.5 fish/set) fell below the normal range for YOY catches in 0.25-in-mesh nets in lakes of this type. Several smallmouth bass were collected in gill nets and trap nets in 2012. Those fish ranged in length from 5.7 to 17.1 inches. Gill net and trap net catches generally don't do a good job of sampling smallmouth bass, and it is hard to judge smallmouth bass abundance based on those catches alone. Several year classes contributed to the 2012 smallmouth bass catch, which included fish up to eight years of age; however, none of the year classes appeared to have been particularly strong. Large numbers of YOY smallmouth bass were collected in 0.25-in-mesh trap nets; the catch (12.6 fish/set) was higher than usual for a lake of this type. The early spring and warm summer may have contributed to the high YOY catch, since YOY smallmouth bass may have been larger than usual for this time of the year, and therefore more readily caught in the sampling gear. Aspen Lake is one of very few lakes in Cook County that support black crappie. The black crappie catch in 0.75-in-mesh trap nets in 2012 was well within the normal range for a lake of this type, and one of the higher catches seen to date in Aspen Lake. Black crappie catches in this lake have never been high; a minimum catch of 0.5 fish/trap net set may be a reasonable and attainable goal based on recent assessment results. Although black crappie may not be abundant in this lake, the lake can produce some larger fish. Most of the black crappie taken in 2012 were over 11 inches in length, and the mean weight for fish taken in trap nets exceeded the normal range. The 2012 catch consisted mostly of four-year-old fish from a moderately strong 2008 year class. The capture of a few YOY black crappie in 0.25-in-mesh trap nets in this assessment (and the size of those fish at capture) suggested another fairly good year class may be produced in 2012.

Aspen Lake continues to be one of the better walleye lakes along Cook County's Gunflint Trail. The walleye catch in 2008 was about average for this lake historically, and for a lake of this class. Most of the walleye collected in 2008 were 16 to 19 inches in length, and most had apparently been produced naturally. Stocking may also have contributed to the 2008 walleye catch, although stocked year classes were no stronger than the unstocked year classes sampled. Northern pike were fairly abundant in Aspen Lake in 2008, but most were young, small fish (under 23 inches in length). Only one northern pike older than three years was taken. Growth rates for northern pike had been fairly fast by Cook County standards, probably due to unusually high numbers of yellow perch found in the lake in 2008. Aspen Lake is one of very few lakes in Cook County to support a black crappie population. The 2008 catch, while low compared to crappie lakes elsewhere in the state, was high for a Cook County lake, and about average for Aspen Lake. Black crappie growth rates had also been faster than average for this area, with fish reaching a length of 5.4 inches at the end of their second year of growth. The 2008 smallmouth bass catch was low, but that was not unusual for this lake, where standard assessment gear has frequently failed to collect any smallmouth bass. Aspen Lake has typically supported better smallmouth bass fishing than assessment catches would indicate.

Based on Minnesota DNR survey data, anglers target Black Crappie, Yellow Perch, Walleye, Smallmouth Bass, and Northern Pike in Aspen. See the full species list above for catch rates, size structure, and quality scores.

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

Aspen has a maximum depth of 29 feet, per Minnesota DNR data.

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

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