Minnesota DNR fisheries surveys · latest August 4, 2025
Species recorded at Alton Lake
7 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 Alton Lake
No stocking record for Alton 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.
Survey results in full
Minnesota DNR's Standard Survey on September 10, 2018 caught 3.58 walleye per gill net at Alton Lake. Length samples in the latest survey that recorded them ran 9–24 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Alton Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is declining. 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: 2025-08-04 (Targeted Survey).
12 surveys on file · most recent 2025-08-04 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Tullibee (Cisco) | 18.70 | 18 in 2018-09-10 | 0.99 lb |
| White Sucker | 5.82 | 7–25 in 2018-09-10 | 2.43 lb |
| Walleye | 2.61 | 9–24 in 2018-09-10 | 2.84 lb |
| Smallmouth Bass | 2.25 | 2–18 in 2018-09-10 | 1.23 lb |
| Rock Bass | 1.80 | 4–8 in 2018-09-10 | 0.27 lb |
| Northern Pike | 0.85 | 11–23 in 2018-09-10 | 3.62 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and 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.
Tullibee (Cisco)
White Sucker
Walleye
Smallmouth Bass
From the 2025-08-04 survey
Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Alton Lake on August 4th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Alton Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — AltonFisheries Lake Survey · MN DNR LakeFinder
Common questions
What fish are in Alton Lake?
Minnesota DNR's Standard Survey on September 10, 2018 caught 3.58 walleye per gill net at Alton Lake. Length samples in the latest survey that recorded them ran 9–24 inches. Minnesota DNR lists 7 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 Alton Lake last surveyed?
The most recent fisheries survey on file for Alton Lake is dated August 4, 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 Alton Lake stocked?
No stocking record for Alton 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.
Do the water-quality readings tell me how Alton Lake fishes?
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Alton Lake’s water-quality measurements separately, and the water-quality trend over 2 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
Water-quality readings are 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 with clear, low-nutrient water can still carry a meal limit on larger predator fish.
Where to stay near Alton Lake
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