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Minnesota DNR fisheries surveys · latest May 6, 2025

Mountain Lake FishingFWater-quality grade F

Minnesota DNR surveys at Mountain Lake average 36.34 largemouth bass per unit of sampling effort (CPUE) across 12 surveys. The most recent is a Targeted Survey dated May 6, 2025. Length samples in the latest survey that recorded them ran 6–19 inches. In Cottonwood County, Minnesota, Mountain Lake carries an overall water-quality grade of F. Water clarity averages 1.2 feet of visibility, and there are 2 public boat landings. The survey figures on this page are Minnesota DNR's own; the water-quality grade comes from EPA Water Quality Portal samples. Neither is a forecast of today's bite.

Species recorded at Mountain Lake

12 species on the Minnesota DNR list for this lake. A species on the list has been recorded here; it does not mean it is catchable today or in every part of the lake.

Stocking at Mountain Lake

Minnesota DNR publishes a stocking history for this lake — which species went in, how many, and in which years. Read the years: a lake stocked in one year is not necessarily stocked in the next.

Getting on the water

2 public boat landings are recorded on Mountain Lake. Minnesota DNR lists the public access sites, including ramp type and parking, in the documents below.

Survey results in full

DNR fisheries survey

Minnesota DNR surveys at Mountain Lake average 36.34 largemouth bass per unit of sampling effort (CPUE) across 12 surveys. The most recent is a Targeted Survey dated May 6, 2025. Length samples in the latest survey that recorded them ran 6–19 inches.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Mountain Lake F from EPA Water Quality Portal chemistry, and the water-quality trend over 2 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.

DNR Fisheries Survey Summary

12 surveys on file from MN DNR Fisheries. Most recent: 2025-05-06 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg catch rate (CPUE)Avg Weight
Black Bullhead62.310.36 lb
Largemouth Bass36.341.11 lb
Bluegill33.010.17 lb
Yellow Perch27.150.19 lb
White Crappie25.440.31 lb

CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE means more abundant in standardized sampling. This is not a weekly bite report.

Length Distributions

Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.

Black Bullhead

92 fish · 612 in · 2022-05-31
442206789101112

Largemouth Bass

37 fish · 619 in · 2025-05-06
1680trophy 20678910111213141516171819

Bluegill

582 fish · 48 in · 2022-05-31
312156045678

Yellow Perch

14 fish · 711 in · 2022-05-31
740trophy 127891011

From the 2025-05-06 survey

Mountain Lake is a 241-acre, class 43 lake, located within the City of Mountain Lake in Cottonwood County. The lake has a maximum depth of 7.0 feet, and has a watershed-to-lake ratio of 22-to-1. In the early 1990's, Mountain Lake had a diverse population of fish. During the winter of 1993-94, the lake suffered a…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mountain Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Common questions

What fish are in Mountain Lake?

Minnesota DNR surveys at Mountain Lake average 36.34 largemouth bass per unit of sampling effort (CPUE) across 12 surveys. The most recent is a Targeted Survey dated May 6, 2025. Length samples in the latest survey that recorded them ran 6–19 inches. Minnesota DNR lists 12 species for the lake in total. Those are survey results, not a catch report: a net set on one date measures what was in that net.

When was Mountain Lake last surveyed?

The most recent fisheries survey on file for Mountain Lake is dated May 6, 2025. Survey intervals vary by lake and by species; a gap of several years between surveys is normal and does not mean the record is missing.

Is Mountain Lake stocked?

Minnesota DNR publishes a stocking history for Mountain Lake. It records which species were released, in what numbers and in which years — the source documents are linked further down this page. A lake can be stocked in some years and not others, so read the years rather than assuming an annual release.

Does the water-quality grade tell me how Mountain Lake fishes?

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Mountain Lake F from EPA Water Quality Portal chemistry, and the water-quality trend over 2 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.

Before you eat what you catch

A water-quality grade is not a consumption advisory. Mercury and PCB advice for Minnesota waters comes from MDH, and it is issued per species and per size class — a lake can grade well and still carry a meal limit on larger predator fish.

Where to stay near Mountain Lake

Top-rated places to stay near Mountain Lake

See the full where-to-stay map for Mountain Lake

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