Deer

Minnesota DNR Fisheries IBI program staff conducted an assessment of lakeshore habitat on Deer Lake on August 13th, 2025, following the Score the Shore survey protocols. The assessment consisted of 29 survey sites evenly spaced 200 meters around the lake. Assessments were made in three habitat zones: Shoreline Zone (the shore-water interface to the top of the natural bank), Shoreland Zone (land-ward from shoreline to development structure or 100 feet), and Aquatic Zone (lake-ward 50 feet of shoreline). The average lakewide habitat score was 86.7 (+/- 2.7) out of 100 possible. A score of 86.7 indicates the lakewide shoreline condition is High (85-91.9). Approximately 24 percent of the sites were developed with a mean score of 72.6 (+/- 9.2) indicating shoreline habitat quality of developed sites is Moderate (70-79.9), while undeveloped sites had a mean score of 91.2 (+/- 1.1) with High (85-91.9) habitat quality.

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Deer Lake on August 4th, 2025, 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. During the summer, 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 the profile from the deepest basin (maximum sampled depth 42.6 feet), the water temperature decreased below 21.2 degrees C (70.2 degrees F) at 17.7 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 17.9 feet at the time of sampling. The thickness of this layer of water in the water column was 0.2 feet, indicating that oxythermal habitat was present but marginal for Cisco. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 21.0 degrees C (69.8 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were marginal for Cisco at the time of the survey as the layer was confined to less than 3 feet of suitable habitat at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2023 indicated suitable oxythermal habitat, with a layer of 3.6 feet. When inadequate oxythermal habitat is available, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Deer Lake on August 4th, 2025, 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. During the summer, 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 the profile from the deepest basin (maximum sampled depth 42.6 feet), the water temperature decreased below 21.2 degrees C (70.2 degrees F) at 17.7 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 17.9 feet at the time of sampling. The thickness of this layer of water in the water column was 0.2 feet, indicating that oxythermal habitat was present but marginal for Cisco. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 21.0 degrees C (69.8 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were marginal for Cisco at the time of the survey as the layer was confined to less than 3 feet of suitable habitat at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2023 indicated suitable oxythermal habitat, with a layer of 3.6 feet. When inadequate oxythermal habitat is available, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

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

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

Deer has a maximum depth of 42 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Deer is from 2021.

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