Minnesota DNR fisheries surveys · latest August 11, 2025
Mary Lake FishingAWater-quality grade A
Minnesota DNR surveys at Mary Lake average 14.95 largemouth bass per unit of sampling effort (CPUE) across 15 surveys. The most recent is a Standard Survey dated August 11, 2025. Length samples in the latest survey that recorded them ran 5–20 inches. In Douglas County, Minnesota, Mary Lake carries an overall water-quality grade of A. Water clarity averages 10.5 feet of visibility, and there is one public boat landing. 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 Mary Lake
17 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 Mary 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
1 public boat landing is recorded on Mary Lake. Minnesota DNR lists the public access sites, including ramp type and parking, in the documents below.
Survey results in full
Minnesota DNR surveys at Mary Lake average 14.95 largemouth bass per unit of sampling effort (CPUE) across 15 surveys. The most recent is a Standard Survey dated August 11, 2025. Length samples in the latest survey that recorded them ran 5–20 inches.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Mary Lake A from EPA Water Quality Portal chemistry, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
15 surveys on file from MN DNR Fisheries. Most recent: 2025-08-11 (Standard Survey).
Top Species by Catch Rate
| Species | Avg catch rate (CPUE) | Avg Weight |
|---|---|---|
| Spottail Shiner | 29.68 | — |
| Bluntnose Minnow | 22.47 | — |
| Bluegill | 15.23 | 0.17 lb |
| Largemouth Bass | 14.95 | 1.03 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.
Bluegill
Largemouth Bass
From the 2025-08-11 survey
Lake Mary (2,450 acres) is located five miles southwest of Alexandria. Water clarity is moderate (8 feet) and aquatic plants are common in shallow areas. Average depth is 17 feet with a maximum depth of 40 feet. Walleye, Northern Pike, Largemouth Bass, and Bluegill are common. Lake Mary has two public accesses. One is…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mary Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MaryFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Mary (0932)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — MaryFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MaryPublic Water Access Sites · MN DNR LakeFinder
Common questions
What fish are in Mary Lake?
Minnesota DNR surveys at Mary Lake average 14.95 largemouth bass per unit of sampling effort (CPUE) across 15 surveys. The most recent is a Standard Survey dated August 11, 2025. Length samples in the latest survey that recorded them ran 5–20 inches. Minnesota DNR lists 17 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 Mary Lake last surveyed?
The most recent fisheries survey on file for Mary Lake is dated August 11, 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 Mary Lake stocked?
Minnesota DNR publishes a stocking history for Mary 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 Mary Lake fishes?
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Mary Lake A from EPA Water Quality Portal chemistry, and the water-quality trend over 6 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 Mary Lake
Top-rated places to stay near Mary Lake
Planning a trip to Mary Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Mary Lake — straight to your inbox. No spam, unsubscribe anytime.