Iron

Iron Lake is a 122-acre lake located 38 miles northwest of Grand Marais off the Gunflint Trail. Public access is through a boat landing near the northwest bay of the lake. Iron Lake was historically managed for walleye. However, supplemental stocking efforts were deemed unsuccessful and stocking discontinued in 2016. Iron Lake is now managed for bluegill and northern pike. The 2023 standard survey was the first of two scheduled surveys to evaluate survival and growth of the bluegill, northern pike, and walleye populations. The bluegill catch was similar to the past few surveys and met the current management goal. It did fall slightly below average for similar lakes in the area. Size structure of bluegill was 3.4 to 10.7 inches with a mean length of about 4 inches. The majority of the fish collected were under 6 inches but a large 10.7 inch bluegill was found in the survey and was aged at 9 years old. Bluegill growth rates were above average compared to other Grand Marais area lakes with the potential to grow large. Northern pike abundance was slightly higher than the previous two surveys and met the current management goal. Catch rates are higher than similar area lakes. Northern pike ranged from 9.1 to 25.2 inches with a mean length 18.4 inches. Iron Lake supports a relatively abundant northern pike population and can provide anglers with good northern pike action. Walleye catch rates were very low and had been relatively low since the 1980s. Catch rates are below average for similar area lakes. The few walleye captured ranged from 13.3 to 19.8 inches with a mean of 12.5 inches. Aging results suggest that most of the fish had been naturally reproduced and grew at average rates compared to other area lakes. Walleye goals continue to be not met in Iron Lake and suggest that the walleye population may not reach desired levels. White sucker catches were similar to previous surveys. Other species collected in small numbers were yellow perch, rock bass, and one splake. Iron has never been stocked with splake and this fish likely swam over from Portage Lake as through a creek connection between the two waterbodies. 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.

Iron Lake is managed for Walleye and Bluegill, although Northern Pike are important in this lake as well (2007 Lake Management Plan). The long range goal for Walleye is to improve their abundance to achieve a minimum gill net catch of 3.0 fish/set. The goal for Bluegill is a population supporting a minimum trap net catch of 1.4 fish/set. Goals for the Northern Pike population are a minimum gill net catch of 1.2 fish/set, with some fish over 25 inches in length present. This was the second of three surveys scheduled in the 2007 lake management plan to monitor the fish community and determine whether Walleye stocking in this lake (resumed in 2008) was effective. In addition, the survey was part of a 2016 Section of Fisheries initiative to evaluate all current Walleye fingerling stocking in the state, on a lake-by-lake basis. The 2016 Walleye gill net catch, while low for a lake of this class, was still one of the higher catches seen in this lake since 1980. Only five year classes contributed to the 2016 catch, and all but one of those had been produced naturally. Walleye growth had apparently been somewhat faster than average, at least in their early years. On average, fish reached a length of 13.8 inches by the end of their fourth year, compared to an area average of 12.6 inches. Walleye fingerling stocking since 2008 does not appear to have met management goals, and seems to have contributed little to the population in this lake. Although Walleye gill net catches in 2012 and 2016 were the highest seen in this lake since 1987, they still fell well short of the long range goal for the species. Although stocking in 2008 and 2010 probably contributed to the 2012 catch, fish from one natural year class (2007) were also collected in that survey. In the 2016 survey, all but one of the Walleye collected came from unstocked year classes. The contribution of stocked year classes in 2016 was limited to a single fish from the 2010 year class. Iron Lake is one of very few lakes in Cook County to support a significant Bluegill population, and has begun attracting some attention from anglers seeking that species. In 2016 the Bluegill trap net catch, and the average size for Bluegill taken in that gear, fell close to the middle of normal ranges for a lake of this type. The 2016 catch was similar to catches seen in this lake since 1984, but the average size of fish taken was fairly high for this lake. Strong year classes produced in 2012 and 2011 accounted for 71% of the Bluegill taken in standard trap nets in 2016, but high catches of smaller fish in small-mesh trap nets suggested the 2015 and 2014 year class may also have been strong. Bluegill growth appeared to have been about average for this area. Fish reached an average length of 6.6 inches by the end of their fifth year, compared to an area average of 6.8 inches. Bluegill as large as 8.4 inches were taken in 2016, and 56% of the fish taken in standard trap nets were six inches or greater in length. The 2016 Northern Pike gill net catch was within the normal range for a lake of this class, and was similar to most past catches in this lake. The long range catch goal for the species was met in 2016, but not the size goal. No Northern Pike 25 inches or larger were captured in any of the sampling gears used in this survey; most were under 22 inches. Reproductive success appeared to have been fairly good, with five year classes contributing to the 2016 catch, but growth had been slow. Forage for Walleye and Northern Pike appeared to have been limited. The Yellow Perch gill net catch was still relatively low, despite showing some improvement between 2012 and 2016. No alternative prey species were collected in small-mesh trap nets, although small Bluegill did seem to be abundant, and may have provided some forage for Northern Pike. White Sucker numbers appeared low, and most would have been too large to be taken by any but the largest Northern Pike present. Although Iron Lake is accessible by boat from Little Iron Lake, anglers should be aware that the channel between the lakes is long, shallow, and choked with vegetation. At one point it is narrow and rocky, and may not be passable in low water.

Iron Lake is managed for walleye and bluegill, although northern pike are important in this lake as well. The long range goal for walleye is to improve their abundance to achieve a minimum gill net catch of 3.0 fish/set. The goal for bluegill is a population supporting a minimum trap net catch of 1.4 fish/set. Goals for the northern pike population are a minimum gill net catch of 1.2 fish/set, with some fish over 25 inches in length present. This was the first of three assessments scheduled in the 2007 lake management plan to monitor the fish community and determine whether walleye stocking in this lake (resumed in 2008) would be effective. In 2012, Clean Water Legacy funding allowed areas across the state to do some nearshore fish community sampling to improve our ability to use a fish-based Index of Biotic Integrity (IBI) to identify disturbed aquatic ecosystems. Scoring criteria for IBIs in northeastern Minnesota lakes have not yet been developed. Iron Lake was selected for nearshore sampling because its accessibility allowed for use of the sampling gears required. Walleye gill net catches in this lake have not exceeded 3.0 fish/set since 1977, despite periods of heavy stocking. The 2012 gill net catch was the highest seen in this lake since 1987, but still fell well short of the long range goal for the species. Although the catch was low, mean weight for the fish that were taken was higher than normal for a lake of this class, and was the highest seen to date in this lake. Although stocking in 2008 and 2010 probably contributed to the 2012 catch, fish from one natural year class (2007) were also collected. Walleye growth had apparently been fast; four-year-old fish reached a mean length of 15.4 inches at the end of their fourth year, compared to a mean of 12.6 inches in similar lakes in the area. Iron Lake is one of very few lakes in Cook County to support a significant bluegill population. Bluegill were fairly abundant in 2012, and some larger fish were present. The bluegill trap net catch, and the mean weight for bluegill taken in trap nets, fell in the middle of normal ranges for a lake of this type. The 2012 catch was similar to catches seen in this lake since 1984, but the average size of fish taken was the highest seen to date. Strong year classes produced in 2006, 2007, and 2010 accounted for 92% of the bluegill taken in gill nets and trap nets in 2012. Growth had been about average for this area. Six-year-old bluegill reached an average length of 7.8 inches at the end of their sixth year, compared to an area mean of 7.9 inches. Bluegill as large as 10.2 inches were taken in 2012, and 60% of the fish taken in trap nets were six inches or greater in length. The 2012 northern pike gill net catch was within the normal range for a lake of this class, and met the long range goal for the species. One fish over 25 inches in length was taken, but most were under 20 inches. Only three age classes contributed to the 2012 catch, and none appeared to have been exceptionally strong. Growth had been average; three-year-old fish reached a mean length of 17.9 inches by the end of their third year. Forage for walleye and northern pike appeared to have been limited. The yellow perch gill net catch was relatively low. Golden shiner were fairly abundant, and may have been more important than yellow perch as a source of forage for walleye and northern pike. Some of the white sucker collected would have been small enough to have provided some forage for the larger northern pike in the lake. Splake taken in this assessment were migrants from Portage Lake, where they have been regularly stocked. Their survival in Iron Lake has been surprisingly good, given the number of predators found in the lake. All the splake taken in 2012 were three-year-old fish from a 2009 stocking of Portage Lake. Sampling of the nearshore fish community was done using quarter-in-mesh trap nets, a 15-ft beach seine, and backpack electrofishing gear. Prior to sampling done in 2012, Iron Lake was known to have supported, at various times, yellow perch, walleye, northern pike, bluegill, white sucker, rock bass, golden shiner, splake, green sunfish, and smallmouth bass. No smallmouth bass had been sampled since 1957, and splake were migrants from Portage Lake, where they have been stocked. Nearshore sampling in 2012 added central mudminnow to the list of species known to be present in this lake.

Based on Minnesota DNR survey data, anglers target Green Sunfish, Walleye, Northern Pike, Bluegill, and Rock Bass in Iron. See the full species list above for catch rates, size structure, and quality scores.

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

Iron has a maximum depth of 19 feet, per Minnesota DNR data.

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

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