Alder

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Alder Lake on August 13th, 2025, 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. During the summer, 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 the profile from the deepest basin (maximum sampled depth 52.5 feet), the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 29.2 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 50.9 feet at the time of sampling. The thickness of this layer of water in the water column was 21.7 feet, indicating that oxythermal habitat was present for Lake Trout. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 7.3 degrees C (45.1 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 late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 4 years, between 1988-2024, indicate suitable oxythermal habitat in most years when surveyed, with the least favorable conditions recorded in 2024 when adequate oxythermal habitat was unavailable. Reviewing recent data, Alder lake has TDO3 measurements ranging from 6.8 to 9.8 degrees C. When adequate oxythermal habitat is unavailable, Lake Trout 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 Alder Lake on August 13th, 2025, 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. During the summer, 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 the profile from the deepest basin (maximum sampled depth 52.5 feet), the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 29.2 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 50.9 feet at the time of sampling. The thickness of this layer of water in the water column was 21.7 feet, indicating that oxythermal habitat was present for Lake Trout. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 7.3 degrees C (45.1 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 late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 4 years, between 1988-2024, indicate suitable oxythermal habitat in most years when surveyed, with the least favorable conditions recorded in 2024 when adequate oxythermal habitat was unavailable. Reviewing recent data, Alder lake has TDO3 measurements ranging from 6.8 to 9.8 degrees C. When adequate oxythermal habitat is unavailable, Lake Trout 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 Alder Lake on August 13th, 2025, 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. During the summer, 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 the profile from the deepest basin (maximum sampled depth 52.5 feet), the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 29.2 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 50.9 feet at the time of sampling. The thickness of this layer of water in the water column was 21.7 feet, indicating that oxythermal habitat was present for Lake Trout. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 7.3 degrees C (45.1 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 late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 4 years, between 1988-2024, indicate suitable oxythermal habitat in most years when surveyed, with the least favorable conditions recorded in 2024 when adequate oxythermal habitat was unavailable. Reviewing recent data, Alder lake has TDO3 measurements ranging from 6.8 to 9.8 degrees C. When adequate oxythermal habitat is unavailable, Lake Trout are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Based on Minnesota DNR survey data, anglers target Walleye, Lake Trout, Northern Pike, Smallmouth Bass, and Yellow Perch in Alder. 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 Alder. Check the DNR LakeFinder page for current access details before you go.

Alder has a maximum depth of 72 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Alder is from 2015. Surveys this old should be treated with some caution — fish populations change over time.

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