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LakeQuality

Mark Twain Lake vs Monroe City Lake B Nr. Dam

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

Monroe City Lake B Nr. Dam has a higher water quality grade (C, Fair) than Mark Twain Lake (D, Poor). Both are in Wisconsin.

Both Mark Twain Lake and Monroe City Lake B Nr. Dam sit in Missouri. 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: Mark Twain Lake (D) and Monroe City Lake B Nr. Dam (C) 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.

D

Mark Twain Lake

Ralls County, Wisconsin

Very murky, less than 2.5 ft of visibility.

C

Monroe City Lake B Nr. Dam

Monroe County, Wisconsin

No clarity data.

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.

MetricMark Twain LakeMonroe City Lake B Nr. Dam
Overall GradeD (Poor)C (Fair)
Water Clarity2.5 ftNo data
Phosphorus60.8 µg/L44 µg/L
Chlorophyll-a (Algae)18.3 µg/LNo data
Maximum Depth--
Surface Area5.9K acres50 acres
Public AccessUnknownUnknown
Fish Species00
Trophic Stateeutrophiceutrophic

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

Verdict

Monroe City Lake B Nr. Dam wins on overall water quality with a Grade C versus Mark Twain Lake's Grade D. For fishing diversity, Monroe City Lake B Nr. Dam also leads with 0 species.