Saganaga

Temperature and dissolved oxygen measurements were collected from the deepest basin in Saganaga Lake on August 7th, 2025. This was done to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake (Lake Whitefish and Cisco, also known as 'Tullibee', are also present). Lake Trout require a layer of oxythermal habitat that contains water temperatures below 8.8 degrees C (47.8 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on data collected from the deepest basin (maximum sampled depth was 89.9 feet), the water temperature decreased to 8.8 degrees C (47.8 degrees F) at 41.0 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 85.7 feet at the time of sampling. This layer in the water column was 44.7 feet, indicating oxythermal habitat for Lake Trout was present. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 6.1 degrees C (43.0 degrees F). TDO3 values cooler than 8.8 degrees C (47.8 degrees F) indicate that oxythermal conditions were suitable for Lake Trout at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the period of maximum oxythermal stress (July 26th to Aug 24th) in 10 years, between 1985-2024, indicated unsuitable oxythermal habitat in most years surveyed, with unfavorable conditions recored in 1992, 2008 when there was no suitable oxythermal habitat layer. When adequate oxythermal habitat is not available, Lake Trout are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Saganaga Lake is 18,766 acres in size and the largest lake in the Grand Marais area. It is located at the end of the Gunflint Trail approximately 56 miles northwest of Grand Marais on the border of Minnesota and Ontario, Canada. Saganaga is currently managed for lake trout and walleye. The Minnesota waters of Saganaga Lake are currently under an experimental walleye regulation implemented in March 2015. That regulation established a bag limit of three fish, with a minimum size limit of 17 inches, and only one fish over 20 inches allowed in possession. The main goal for the regulation was to improve walleye recruitment and increase the walleye population that had declined considerably by the early 2000s. To help evaluate this regulation standard surveys were scheduled for 2017, 2020, and 2023. The walleye catch in gill nets fell below the management goal but was lightly higher than when the regulation was implemented. Walleye catch rates are still higher than in other similar area lakes. Walleye ranged between 8.3 to 29.2 inches with a mean length of 13.4 inches. More than 10% of walleye were larger than 20 inches in size, with some lunkers found close to 30 inches. Back calculated age estimates found a total of 9 year classes present, with the strongest year classes in 2020 and 2021. Fry stocking was conducted in 2021 and could have bolstered that year class but it is likely natural recruitment drives the walleye population. Walleye growth rates continue to be slightly faster than area averages with age 5 fish being over 17 inches in size. The lake trout catch in gill nets was slightly higher than previous surveys but was relatively low and did not meet the management goal. Lake trout collected ranged from 13.9 to 24.2 inches with an average length of 19.6 inches. Aging results found those fish came from 3 naturally reproduced year classes with the oldest individual being 16 years old. Northern pike catch rates were in the upper end of the normal range for the lake in 2023, and higher than similar lakes in the area. Size structure of the northern pike collected ranged from 19.9 to 36.3 inches with a mean length of 25.8 inches. Saganga Lake holds good numbers of northern pike with many of them large sized. Although anglers have reported catching more smallmouth bass, catch rates in gill net surveys have remained consistent over a couple of decades. Additional bass specific surveys may be needed to evaluate population growth. Smallmouth bass ranged from 10.6 to 17.1 inches with a mean length of 13.9 inches and should be of interest to anglers. Black crappie were sampled for the first time in Saganaga Lake in 2014 and were found again in the 2023 survey. Catch rates remain low, but indicate the population continues to persist. Black crappie were 7.6 to 11.6 inches in size with a good mean length of 9.5 inches. Fishable black crappie populations are uncommon in this area and provide a unique angling opportunity. In addition to lake trout, Saganaga Lake continues to support other cold-water fish species like cisco, lake whitefish, burbot, and rainbow smelt. Catch rates for cisco, lake whitefish, and rainbow smelt were relatively low, while burbot abundance was average for Saganaga lake in 2023. Although lower in abundance cisco and rainbow smelt should still provide good forage for lake trout. Anglers have been known to target lake whitefish and cisco in this lake with some success. Saganaga Lake is infested with the invasive zooplankton called spiny waterflea. Anglers leaving the lake should dry and clean their equipment thoroughly before moving to another lake to prevent the spread of this aquatic invasive species. 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.

Saganaga Lake is an Ontario border water that is currently managed for Lake Trout and Walleye. The goal for Lake Trout is to maintain a minimum catch in deep gill net sets (GDE) of 1.0 fish/set, with some fish over 25 inches present. The goal for Walleye is to increase the catch in shallow gill net sets (GSH) to 6.0 fish/set, with some fish over 30 inches present. Minnesota waters of Saganaga Lake are currently covered by an experimental Walleye regulation, implemented in March 2015 with a 2025 end date. That regulation established a bag limit of three fish, with a minimum size limit of 17 inches, and only one fish over 20 inches allowed in possession. The main goal for the regulation was to improve Walleye recruitment. Indicators of success were to have been a gill net catch (deep and shallow sets combined) for Walleye exceeding 5.5 fish/set, with the catch of fish under 17 inches exceeding 3.0 fish/set, and with 10% of Walleye taken exceeding 20 inches in length. To evaluate this regulation, standard surveys were scheduled for 2017, 2020, and 2023, with summer creel surveys planned in 2022 and 2023. The 2017 standard survey was meant to provide some indication of potential Walleye year class strengths early in the evaluation period. Budget cuts and a staff shortage resulted in the that survey, meant to cover the entire lake, being changed to a targeted survey covering only Minnesota waters (but including all gill net sets used in the past in those waters). Fortunately, a review of past assessment data indicated that Walleye catches in Minnesota waters have generally been about the same, have shown the same trends, and have included fish of about the same size, as catches for the entire lake. In 2020 an even more severe staff shortage, coupled with the closure of the Canadian border during the Covid-19 pandemic, again resulted in a switch from the planned standard survey to a targeted survey covering only Minnesota waters. Walleye remained present in fair numbers in 2020, although there was no sign those numbers had increased due to stocking or the special regulation. The lake continued to produce some large walleye. The 2020 Walleye catch in shallow gill net sets was similar to other catches seen in that gear since 2004. The catch again fell well short of the goal from the current (2016) lake management plan. No Walleye over 30 inches were taken; however, the catch included several fish close to that size. The 2020 gill net catch (deep and shallow sets combined) was similar to catches seen in Minnesota waters since 2004, but was lower than any catches seen prior to that year. In contrast, the mean weight for Walleye taken in Minnesota waters in 2020 (2.40 lb/fish) was the highest seen in this lake since 1985. Twenty-nine percent of Walleye taken in 2020 exceeded 20 inches in length, and the gill net catch rate for fish of that size (0.80 fish/set) was the highest seen since 1979. The catch of Walleye under 17 inches in length (1.50 fish/set) was low for this lake, and remained well short of the benchmark for success established for the experimental regulation. One of the purposes of this survey was to continue evaluating Walleye fry stocking that began in 2009. The 2020 catch included some fish from stocked years (not necessarily stocked fish), but the three strongest year classes sampled had been produced naturally (2019, 2016, and 2015). A good natural year class produced in 2012 and seen in the 2014 and 2017 surveys was still contributing to the catch in 2020. Together, unstocked year classes accounted for about 77% of the 2020 walleye catch. In the 2017 survey, fish from unstocked years accounted for about 80% of the catch, and the strongest year classes seen that year had also been produced naturally. While stocking done to date may have contributed some fish to the population, it appeared that natural reproduction remained the most important contributor. Growth of Walleye collected in 2020 appeared to have been about average for a Class 1 lake in this area. Fish reached a mean length of 17.1 inches at the end of their fifth year, compared to an area average of 16.4 inches. Growth rates of young (six years old or younger) Walleye taken in surveys of Saganaga Lake since 2000 have been slower than those measured in earlier years. At current rates, it typically takes five or six seasons of growth for Walleye to reach a length of 17 inches in this lake. Lake Trout numbers remained strong in 2020. The Lake Trout catch in deep gill net sets in Minnesota waters in 2020 indicated management goals for the species in Saganaga Lake were probably met. The catch in deep gill net sets was similar to other catches observed in that gear in this lake since 1964, and exceeded the management goal of 1.0 fish/set. The size goal was met by the capture of one 26-inch fish. The total sample size (10 fish) was too low to allow year class strengths or growth rates to be described with any confidence; however, seven naturally-produced year classes contributed to the catch, and fish as old as nineteen years were seen. The 2020 Northern Pike catch in deep and shallow gill net sets appeared to have bounced back from a low seen in 2017, and was more typical of catches seen in this lake historically. The mean weight for those fish was also more typical of means seen in past surveys. From their length frequency distribution it seemed clear that several year classes had contributed to the 2020 catch; however, no northern pike aging was done in this survey. Smallmouth Bass remained fairly abundant in Saganaga Lake in 2020. Like past assessments, the 2020 survey provided no evidence for an increase in Smallmouth Bass abundance or size in this lake over the last 30 years, although anglers continue to report that Smallmouth Bass have become much more common. Most of the gill net sets used in surveys of Saganaga Lake have been set well off shore, so might not detect any expansion in bass numbers. The 2020 Smallmouth Bass catch in deep and shallow gill net sets combined was similar to catches seen in Minnesota waters since 1985. Smallmouth Bass collected in gill nets in 2020 ranged in length from 5.1 to 15.5 inches. The Yellow Perch catch in shallow gill net sets in 2020 was below the normal range for a lake of this type, and was the lowest ever observed in this lake. Yellow Perch were never abundant in Saganaga Lake, but catches since 2001 have been low, even for this lake. With Cisco in a range of sizes, and fair numbers of rainbow smelt, available as forage a lack of Yellow Perch is probably not a factor limiting Walleye or Northern Pike in this lake. Black Crappie were sampled for the first time in Saganaga Lake in 2014. Although none were collected in this survey, they are certainly still present. A few were collected in a survey of Gull Lake (a connected water) in 2017, and some anglers continue to target the species in the winter in Saganaga Narrows. In addition to Lake Trout, Saganaga Lake continues to support other cold-water fish species, including Cisco, Lake Whitefish, Burbot, and Rainbow Smelt. In this survey Rainbow Smelt were collected most effectively in small-mesh gill nets used to target the species. That catch was low for this lake, historically. Catches of the other three species in deep gill net sets were similar to catches seen in this lake since 1992. Lake Whitefish and Burbot catches fell within normal ranges for that sampling gear, in the Grand Marais area, while the 2020 Cisco catch exceeded the normal range for the gear in this area. Anglers have been known to target Lake Whitefish and Cisco in this lake, with some success. Saganaga Lake is infested with spiny waterflea. Anglers leaving the lake should dry and clean their equipment thoroughly before moving to another lake to prevent the spread of this invasive and harmful aquatic invader.

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

We don't have a confirmed public access point on record for Saganaga. Check the DNR LakeFinder page for current access details before you go.

Saganaga has a maximum depth of 280 feet, per Minnesota DNR data.

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

Yes — Saganaga has confirmed spiny waterflea. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.