Blue

Temperature and dissolved oxygen measurements were collected from the deepest basin in Blue Lake on August 7th, 2025. This was done to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. Cisco require a layer of oxythermal habitat that contains water temperatures below 21.2 degrees C (70.2 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on data collected from the deepest basin (maximum sampled depth was 80.0 feet), the water temperature decreased to 21.2 degrees C (70.2 degrees F) at 22.0 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 36.9 feet at the time of sampling. This layer in the water column was 14.9 feet, indicating oxythermal habitat for Cisco 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 8.2 degrees C (46.8 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were suitable for Cisco 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 6 years, between 2009-2024, also indicated suitable oxythermal habitat in all years surveyed, with the least favorable conditions recorded in 2016 when the suitable oxythermal habitat layer was 9.9 feet thick. When adequate oxythermal habitat is not available, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Blue Lake is located seven miles northeast of Park Rapids in Hubbard County. Blue Lake has a surface area of 336 acres and a maximum depth of 84 feet. There is a DNR-owned public access with a concrete ramp located on the northwest shore of the lake off Half Moon Road. Blue Lake is known for its exceptional water clarity and sandy shorelines. The Minnesota Department of Natural Resources (DNR) has classified Minnesota's lakes into 43 different types based on physical and chemical characteristics. Blue Lake is in Lake Class 23. Class 23 lakes are characterized by having hard water, deep basins, and very high water clarity. Other area lakes in this same classification include Benedict, Boot, East Crooked, Ninth and Eleventh Crow Wing, LaSalle, and Spearhead. Blue Lake has an excellent Walleye population, both in terms of numbers and size of fish. Walleye abundance has been high the past several surveys. A strong age 2-year class was present with most Walleyes in the 12 to 15 inch size range being sampled with fish measured up to 30.8 inches. An abundant Tullibee (Cisco) population provides an excellent forage base for the growth of larger Walleye. However, Yellow Perch, an important forage species for Walleye were sampled in low numbers compared to past surveys. Blue Lake is stocked in the fall with Rainbow Trout fingerlings during even numbered years to provide a bonus fishery. No Rainbow Trout were sampled in the survey. Rainbow Trout stocking began in 1984, and trout have been sampled in low numbers in past surveys. Blue Lake was opened to winter angling in 2007. Angler reports and success for Rainbow Trout have been limited for both the open water and ice angling season. Not known for Panfish, Blue Lake does support populations of Black Crappie, Bluegill, and Pumpkinseed. Anglers will find low to moderate numbers of Black Crappie, with a few larger fish present. A moderate Bluegill and Pumpkinseed population is present in Blue Lake, however, size of fish run small, with few fish over 7.0 inches sampled. Currently no aquatic invasive species (AIS) have been identified in Blue Lake. To avoid spreading AIS, lake users are required to remove all aquatic plants or animals from their watercraft and drain all water from their boat before leaving.

Blue Lake is located seven miles northeast of Park Rapids in Hubbard County. Blue Lake has a surface area of 336 acres and a maximum depth of 84 feet. There is a state-owned public access with a concrete ramp located on the northwest shore of the lake. Blue Lake is known for its exceptional water clarity and sandy shorelines. Blue Lake has a very good Walleye population and gives anglers a chance at a trophy sized fish. Rainbow Trout are stocked in the lake and can provide a bonus fishery. The Minnesota Department of Natural Resources (DNR) has classified Minnesota's lakes into 43 different types based on physical and chemical characteristics. Blue Lake is in lake class 23. Class 23 lakes are characterized by having hard water, deep basins, and very high water clarity. Other area lakes in this same classification include Boot, East Crooked, and Eleventh Crow Wing. Blue Lake has an excellent Walleye population, both in terms of numbers and size of fish. Walleye abundance has been high the past several surveys. Good numbers of Walleye in the 14 to 18 inch size range were sampled with fish measured up to 31.4 inches. An abundant Tullibee (Cisco) population provides an excellent forage base for the growth of larger Walleye. However, Yellow Perch, an important forage species for Walleye were sampled in low numbers compared to past surveys. Blue Lake is stocked in the fall with Rainbow Trout fingerlings during even numbered years. Four Rainbow Trout were sampled in the survey and ranged in length from 11.5 to 17.7 inches. Rainbow Trout stocking began in 1984 and trout have been sampled in low numbers in past surveys. Blue Lake was open to winter angling in 2007. Angler reports and success for Rainbow Trout have been limited for both the open water and ice angling season. While not known for Panfish, Blue Lake does support populations of Black Crappie, Bluegill, and Pumpkinseed. Anglers will find low to moderate numbers of Black Crappie, with a few larger fish present. A moderate Bluegill and Pumpkinseed populations are present in Blue Lake, however, size of fish run small, with few fish over 7.0 inches sampled. Largemouth Bass and Smallmouth Bass populations are also present in Blue Lake in low numbers when compared to surrounding lakes. Largemouth Bass are the more common of the two species, while Smallmouth Bass are present in low numbers. Present and past surveys have shown very low Northern Pike numbers in Blue Lake. Northern Pike were not sampled in the 2019 survey. While Northern Pike abundance is low, the abundant forage base of Tullibee (Cisco) and White Sucker can produce some big Northern Pike. Currently no aquatic invasive species (AIS) have been identified in Blue Lake. To avoid spreading AIS, lake users are required to remove all aquatic plants or animals from their watercraft and drain all water from their boat before leaving.

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

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

Blue has a maximum depth of 84 feet and a mean depth of 44 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Blue is from 2024.

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