Mountain

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Mountain Lake on August 12th, 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 167.3 feet), the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 34.2 feet and the dissolved oxygen concentration stayed greater than 3.0 mg/L throughout the entire sampled depth. This layer in the water column was 133.0 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 never reached because dissolved oxygen remained above 3.0 mg/L throughout the sampled depths. In this case, the minimum temperature, 4.6 degrees C (40.3 degrees F), was substituted as TDO3. 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) from 1955-2024, also indicate suitable oxythermal habitat in the four years surveyed. 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 Mountain Lake on August 12th, 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 167.3 feet), the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 34.2 feet and the dissolved oxygen concentration stayed greater than 3.0 mg/L throughout the entire sampled depth. This layer in the water column was 133.0 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 never reached because dissolved oxygen remained above 3.0 mg/L throughout the sampled depths. In this case, the minimum temperature, 4.6 degrees C (40.3 degrees F), was substituted as TDO3. 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) from 1955-2024, also indicate suitable oxythermal habitat in the four years surveyed. 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 Mountain Lake on August 12th, 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 167.3 feet), the water temperature decreased below 8.8 degrees C (47.8 degrees F) at 34.2 feet and the dissolved oxygen concentration stayed greater than 3.0 mg/L throughout the entire sampled depth. This layer in the water column was 133.0 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 never reached because dissolved oxygen remained above 3.0 mg/L throughout the sampled depths. In this case, the minimum temperature, 4.6 degrees C (40.3 degrees F), was substituted as TDO3. 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) from 1955-2024, also indicate suitable oxythermal habitat in the four years surveyed. 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 Lake Trout and Smallmouth Bass in Mountain. See the full species list above for catch rates, size structure, and quality scores.

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

Mountain has a maximum depth of 210 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Mountain is from 2011. Surveys this old should be treated with some caution — fish populations change over time.

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