Thirteen Lake
Thirteen Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14 ft visibility. Maximum depth: 17 ft. Surface area: 80 acres.
- Clarity
- 14 ft
- Max depth
- 17 ft
- Area
- 80 acres
- Trend
- ↑ Improving
- Public access
- No
- Ice-out
- Apr 28
Next lake in St. Louis County
Why Thirteen Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Thirteen Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Thirteen Lake is a 80-acre lake in St. Louis County, Minnesota with a maximum depth of 17 feet. 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 2025-08-29. Grade methodology: LakeGrade methodology.
Watch Thirteen Lake water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Thirteen Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 14 ft. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Thirteen Lake
Compare lakeside cabins, hotels, and vacation rentals near Thirteen Lake in St. Louis County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Thirteen Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 17 ft |
| Surface Area | 80 acres |
| Shoreline Length | 1.4 mi |
| Littoral Zone | 91% |
| Public Access | No |
Fishing Thirteen Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1987-08-31 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Northern Pike | 3.96 | 3.72 lb |
| Bluegill | 1.46 | 0.27 lb |
| Yellow Perch | 1.33 | 0.15 lb |
| White Sucker | 1.00 | 3 lb |
| Pumpkinseed | 0.29 | 0.1 lb |
| Smallmouth Bass | 0.29 | 1.4 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
From the 1987-08-31 survey
NORTHERN PIKE NUMBERS ARE HIGH AT 7.7/GILLNET. LOW NUMBERS OF BLUEGILL AND PUMPKINSEED.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Thirteen Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — ThirteenFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.237 m/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (4 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2002-04-19 (2002) | 2022-05-07 (2022) |
Most recent ice-out: 2022-05-07
EPA Impairment Status
Thirteen Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN69-0793-00 · Official waterbody report · Matched by proximity (1.5 km)
Graded lakes near Thirteen Lake
Thirteen Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in St. Louis County
Frequently asked questions about Thirteen Lake
What is the water quality grade for Thirteen Lake?
- Thirteen Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14 ft visibility. Maximum depth: 17 ft. Surface area: 80 acres.
Is Thirteen Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Thirteen Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Thirteen Lake?
- Thirteen Lake has a maximum depth of 17 feet. The lake covers 80 acres.
When does Thirteen Lake thaw?
- Thirteen Lake typically has ice-out around Apr 28.
Explore Thirteen Lake across LakeGrade
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Where this data comes from
38 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA38 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate