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LakeQuality

Blackduck Lake vs Medicine Lake

Water quality, depth, fish species, and recreation comparison.

Medicine Lake has a higher water quality grade (B, Good) than Blackduck Lake (C, Fair). Both are in Beltrami County, Minnesota.

Both Blackduck Lake and Medicine Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. The grades are close: Blackduck Lake (C) and Medicine Lake (B) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.

With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.

C

Blackduck Lake

Beltrami County, Minnesota

Murky, only visible to about 6.2 ft.

B

Medicine Lake

Beltrami County, Minnesota

Moderate clarity, visible to about 7.9 ft.

Side-by-Side Metrics

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

MetricBlackduck LakeMedicine Lake
Overall GradeC (Fair)B (Good)
Water Clarity6.2 ft7.9 ft
Phosphorus39.5 µg/L22 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth28 ft44 ft
Surface Area2.7K acres461.28 acres
Public AccessYesYes
Fish Species11
Trophic Stateeutrophicmesotrophic

Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).

Verdict

Medicine Lake wins on overall water quality with a Grade B versus Blackduck Lake's Grade C. Water clarity: 7.9 ft vs 6.2 ft. For fishing diversity, Medicine Lake also leads with 1 species.