Ace Lake
St. Louis County, Minnesota318 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Ace Lake. Here is what has been measured.
- 8 ft max depth
- Limited data
Ace Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 8 ft visibility. Maximum depth: 8 ft. Surface area: 317.76 acres.
Minnesota DNR's Standard Survey on August 4, 1997 caught 7.50 walleye per gill net at Ace Lake. Length samples in the latest survey that recorded them ran 9–21 inches. DNR survey details →
Ace Lake is a 318-acre lake in St. Louis County, Minnesota with a maximum depth of 8 feet (3-foot average). Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-14. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Ace Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Ace Lake
These are the measurements Minnesota PCA publishes for Ace Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 8 ft. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Ace Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on August 4, 1997 caught 7.50 walleye per gill net at Ace Lake. Length samples in the latest survey that recorded them ran 9–21 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ace Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1997-08-04 (Standard Survey).
1 survey on file · most recent 1997-08-04 (Standard Survey)
29 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| White Sucker | 25.00 | 7–18 in 1997-08-04 | 2.31 lb |
| Northern Pike | 6.88 | 5–30 in 1997-08-04 | 2.73 lb |
| Yellow Perch | 4.46 | 1–9 in 1997-08-04 | 0.12 lb |
| Walleye | 3.92 | 9–21 in 1997-08-04 | 1.54 lb |
| Rock Bass | 2.67 | 3–10 in 1997-08-04 | 0.57 lb |
| Pumpkinseed | 0.42 | 4–7 in 1997-08-04 | 0.4 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.
White Sucker
Northern Pike
Yellow Perch
Walleye
From the 1997-08-04 survey
King is a 293 acre lake located 4 miles south of Rollins, MN off county #266. Stewart has difficult access from the Rossini Trail across a minimum maintenance road to the south side of the lake. Maximum depth is 8 feet and 99% of the lake is shallower than 15 feet. Walleye abundance indexed with assessment nets was…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Ace Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — KingFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — KingFish Stocking History · MN DNR LakeFinder
Lake Details
Max depth
8 ft
Average depth
3 ft
Surface area
318 acres
Shoreline
5.5 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
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Stays near Ace Lake
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Fishing Ace Lake
Water Quality Trend: Improving
Based on 4 years of monitoring (2021–2025).
Water clarity
Improving4 years
Nearby Lakes in St. Louis County
Frequently asked questions about Ace Lake
Where is Ace Lake?
- Ace Lake is a lake in St. Louis County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Ace Lake?
- Ace Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 8 ft visibility. Maximum depth: 8 ft. Surface area: 317.76 acres.
Is Ace Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Ace Lake?
- Ace Lake has a maximum depth of 8 feet and an average depth of 3 feet. The lake covers 317.76 acres.
What did the DNR fisheries survey find at Ace Lake?
- Minnesota DNR's Standard Survey on August 4, 1997 caught 7.50 walleye per gill net at Ace Lake. Length samples in the latest survey that recorded them ran 9–21 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ace Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Ace Lake?
- Public access to Ace Lake is listed as no on the lake record, so confirm before you make the trip. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Ace Lake across LakeQuality
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Where this data comes from
11 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA11 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake details from Minnesota DNR LakeFinder