Minnesota DNR fisheries surveys · latest May 31, 2022
Union Lake FishingCWater-quality grade C
Minnesota DNR surveys at Union Lake average 4.66 largemouth bass per unit of sampling effort (CPUE) across 15 surveys. The most recent is a Targeted Survey dated May 31, 2022. Length samples in the latest survey that recorded them ran 3–20 inches. In Wright County, Minnesota, Union Lake carries an overall water-quality grade of C. Water clarity averages 5.5 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 Union Lake
15 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 Union Lake
No stocking record for Union Lake appears in the Minnesota DNR material on file. That is an absence in the published record, not a confirmation that the lake is unstocked — some waters are managed as naturally reproducing and never appear in a stocking list at all.
Getting on the water
1 public boat landing is recorded on Union 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 Union Lake average 4.66 largemouth bass per unit of sampling effort (CPUE) across 15 surveys. The most recent is a Targeted Survey dated May 31, 2022. Length samples in the latest survey that recorded them ran 3–20 inches.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Union Lake C from EPA Water Quality Portal chemistry, and the water-quality trend over 3 years of monitoring is declining. 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: 2022-05-31 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg catch rate (CPUE) | Avg Weight |
|---|---|---|
| Bluegill | 38.06 | 0.2 lb |
| Black Crappie | 9.46 | 0.23 lb |
| Yellow Perch | 6.90 | 0.1 lb |
| Black Bullhead | 6.34 | 0.51 lb |
| Largemouth Bass | 4.66 | 1.21 lb |
| Yellow Bass | 4.02 | 0.61 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
Black Crappie
Yellow Perch
Black Bullhead
From the 2022-05-31 survey
Union is a small-sized lake (93 acres) located southwest of the City of South Haven in Wright County. Union has 1.5 miles of shoreline and a maximum depth of 35 feet. A state-owned public access with a cement boat ramp and a very small amount of parking is present on the south shore. Water clarity is typically fair to…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Union Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — UnionFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Union (2022)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — UnionPublic Water Access Sites · MN DNR LakeFinder
Common questions
What fish are in Union Lake?
Minnesota DNR surveys at Union Lake average 4.66 largemouth bass per unit of sampling effort (CPUE) across 15 surveys. The most recent is a Targeted Survey dated May 31, 2022. Length samples in the latest survey that recorded them ran 3–20 inches. Minnesota DNR lists 15 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 Union Lake last surveyed?
The most recent fisheries survey on file for Union Lake is dated May 31, 2022. 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 Union Lake stocked?
No stocking record for Union Lake appears in the Minnesota DNR material on file. That is not the same as a confirmed unstocked lake: it means no stocking document was published for it in the records this page draws on.
Does the water-quality grade tell me how Union Lake fishes?
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Union Lake C from EPA Water Quality Portal chemistry, and the water-quality trend over 3 years of monitoring is declining. 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 Union Lake
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