Pine Mountain

Pine Mountain Lake (DOW # 11-0411; Lake Class 22) is a 1,612 acre lake with 737 littoral acres, 9.4 miles of shoreline, and a maximum depth of 80 feet located in Backus, MN. There is a city-owned public access on the east shore. The Minnesota Department of Natural Resources (MNDNR) has classified Minnesota's lakes into 43 different classes based on physical, chemical and other characteristics. Pine Mountain Lake is in Lake Class 22; lakes in the class are generally clear, large, deep lakes with a low percentage of shallow water area and have irregularly shaped shorelines with many bays or points. Other area lakes in this class include Little Boy, Steamboat, Ten Mile and Wabedo. Pine Mountain Lake is primarily managed for Northern Pike and Walleye and secondarily for Tullibee (Cisco), Bluegill, Largemouth Bass, Black Crappie and Yellow Perch. A standard lake survey was completed in 2025. Pine Mountain Lake is an excellent Walleye and Northern Pike lake in the Walker area. Northern Pike were abundant and ranged in length from 14 to 29 inches with an average length of 22 inches. Northern Pike size restrictions and possession limits for Pine Mountain Lake are defined in the North Central Zone Northern Pike regulation and anglers are encouraged to harvest Northern Pike under 22 inches long. Walleye abundance declined slightly in the 2025 survey, and were slightly below management goals. Walleye ranged in length from 8 to 25 inches with an average length of 18 inches. Most of the Walleye sampled were between 14 and 19 inches long. Walleye fry are stocked during odd years, and eight consecutive year-classes were sampled. Bluegill abundance increased from recent surveys, exceeding management goals and provide quality angling opportunities. Bluegill ranged in length from 2 to 10 inches with an average length of 5 inches. Largemouth Bass up to 18 inches were sampled. Black Crappie ranged in length from 6 to 13 inches with an average length of 10 inches. Yellow Perch abundance increased from previous surveys and sampled perch ranged in length from 5 to 9 inches. Other fish species that anglers can expect to encounter include Bowfin (Dogfish), Brown Bullhead, Hybrid Sunfish, Pumpkinseed, Rock Bass, Tullibee (Cisco), White Sucker, and Yellow Bullhead. People can have significant impacts on lakes and the fish populations they support. Harvest, lakeshore development, removal of shoreline vegetation, and introductions of invasive species can all adversely affect fish populations. Currently Pine Mountain Lake is infested with Zebra Mussel, and Curly Leaf Pondweed. Aquatic Invasive Species (AIS) are moved from infested to non-infested waters by anglers, boaters, and lake shore owners and can adversely impact lakes and fish populations. 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 the access. If you suspect an infestation of an invasive species in this lake, save a specimen and report it to a local natural resource office. Additional information on all of these topics can be found on the DNR website (www.dnr.state.mn.us) or by contacting the Walker Area Fisheries office.

Pine Mountain Lake is a 1,612 acre lake with 9.44 miles of shoreline and a maximum depth of 80 feet located in Backus, MN. There is a city-owned public access on the east shore. The Minnesota Department of Natural Resources (MNDNR) has classified Minnesota's lakes into 43 different classes based on physical, chemical and other characteristics. Pine Mountain Lake is in Lake Class 22; lakes in the class are generally clear, large, deep lakes with a low percentage of shallow water area and have very irregularly shaped shorelines with many bays or points. Other Lake Class 22 lakes in the Walker Area include Baby, Big Sand, Ponto, and Stony lakes. A standard lake survey was completed in 2022. Pine Mountain Lake is an excellent Walleye and Northern Pike lake in the Walker area. Walleye abundance was the highest recorded in 2022. Walleye ranged in length from 8 to 28 inches with an average length of 16 inches. Most of the Walleye sampled were between 12 and 15 inches long. Walleye fry are stocked during odd years and eleven consecutive year-classes were sampled. Northern Pike were abundant and ranged in length from 14 to 34 inches with an average length of 21 inches long. Northern Pike size restrictions and possession limits for Pine Mountain Lake are defined in the North Central Zone Northern Pike regulations. Anglers are encouraged to harvest Northern Pike under 22 inches long. Black Crappie and Bluegill numbers were within management goals and provide quality angling opportunities. Black Crappie ranged in length from 5 to 13 inches with an average length of 11 inches. Bluegill ranged in length from 3 to 10 inches with an average length of 6 inches. Largemouth Bass up to 18 inches long were sampled. Yellow Perch were abundant but small in size averaging 7 inches long and ranging in length from 5 to 9 inches. Other fish species that anglers can expect to encounter include Bowfin (Dogfish), Brown Bullhead, Hybrid Sunfish, Pumpkinseed, Rock Bass, Tullibee (Cisco), White Sucker, and Yellow Bullhead. People can have significant impacts on lakes and the fish populations they support. Harvest, lakeshore development, removal of shoreline vegetation, and introductions of invasive species can all adversely affect fish populations. Currently Pine Mountain Lake is infested with Zebra Mussel, and Curly Leaf Pondweed. Aquatic Invasive Species (AIS) are moved from infested to non-infested waters by anglers, boaters, and lake shore owners and can adversely impact lakes and fish populations. 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 the access. If you suspect an infestation of an invasive species in this lake, save a specimen and report it to a local natural resource office. Additional information on all of these topics can be found on the DNR website (www.dnr.state.mn.us) or by contacting the Walker Area Fisheries office.

A targeted survey of the nearshore and littoral fish community, as well as coldwater habitat, in Pine Mountain Lake was conducted by Fisheries Index of Biological Integrity (IBI) Program Staff from 1-4 August 2022. Eighteen sampling sites were evenly spaced around the lake and each was sampled by backpack electrofishing and seining with a 15-foot or 50-foot seine, where possible. Backpack electrofishing was completed at all 18 sites with four sites sampled from the boat due to dense vegetation and deep, fine sediments. A 50-foot seine was used to sample twelve sites, a 15-foot seine was used at two sites, and soft sediments with abundant vegetation and deep water prevented the use of seines at four sampling sites. Nearshore sampling captured 24 native species of fish including nine species that are intolerant of disturbance (Banded Killifish, Blackchin Shiner, Blacknose Shiner, Burbot, Iowa Darter, Logperch, Mimic Shiner, Mottled Sculpin, and Rock Bass) and one species (Fathead Minnow) that is tolerant of disturbance. A concurrent summer trap net survey was conducted on 1-4 August 2022 by IBI Program Staff. Fifteen trap nets were set along the shoreline that encompassed multiple habitat types. Bluegill comprised a majority of the trap net catch by number and Bowfin and Bluegill comprised a majority of the catch by biomass. The number of Bluegill sampled per net was near but above 50% quartile for similar Lake Class 22 lakes and the average length was 6.3 inches, with 41% over 7 inches. The nearshore and trap net data were combined with gill net data from an August 2022 survey to describe the fish community and provide a Fish-based IBI (FIBI) score. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (e.g., Blackchin Shiner, Iowa Darter, and Rock Bass), while other species are tolerant of degraded conditions (e.g., Black Bullhead, Fathead Minnow, and Green Sunfish). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website. A temperature-dissolved oxygen profile was collected in the deepest basin on Pine Mountain Lake on August 1st, 2022 to evaluate the amount of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee. Based on the profile, the top of the thermocline (i.e., the location in the water column with the sharpest transition from warm to cold water) occurred at approximately 30 feet. Dissolved oxygen decreased to below 3.0 mg/L at 28.7 feet, which was above the thermocline, at the time of sampling. The temperature at which dissolved oxygen decreased to below 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 21.2°C (70.2°F ). TDO3 values near 21.5°C indicate that oxythermal conditions are marginal to poor for Cisco. Low dissolved oxygen concentrations (less than 3 mg/L) near the thermocline and warm surface temperatures would limit Cisco distribution within the water column. Data collected in 1998-2019 further indicate marginal to poor oxythermal habitat in most years, with the least favorable conditions recorded in 2005 and 2008. When inadequate oxythermal habitat is available, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress. Results from this survey agree with the presence of an exceptional fish community indicated from a 2019 survey. Data from this survey indicates that the warmwater fish community in Pine Mountain Lake is in good health as indicated by an exceptionally high FIBI score above the impairment threshold for aquatic life use determined for similar lakes. However, the TDO3 that indicated coldwater habitat conditions were marginal to poor for Cisco at the time of the survey. Data from this survey will contribute biological information about the health of the fish community, and the coldwater habitat, to the Pine River Watershed assessment process in coordination with MN Pollution Control Agency.

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

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

Pine Mountain has a maximum depth of 80 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Pine Mountain is from 2025.

Yes — Pine Mountain has confirmed zebra mussel. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.