Shell Lake
Shell Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 9 ft visibility. Maximum depth: 15 ft. Surface area: 493.3 acres.
- Clarity
- 9 ft
- Max depth
- 15 ft
- Area
- 493 acres
- Trend
- ↑ Improving
- Public access
- No
Next lake in St. Louis County
Why Shell 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 Shell Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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.
Shell Lake is a 493-acre lake in St. Louis County, Minnesota with a maximum depth of 15 feet. Overall water quality is improving over recent sampling years. The lake supports 8 documented fish species including bluegill, largemouth bass, and northern pike. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-06-24. Grade methodology: LakeGrade methodology.
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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 Shell Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 9 ft. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Shell Lake
Compare lakeside cabins, hotels, and vacation rentals near Shell 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 Shell Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Shell Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (54,450 cells/mL) on April 25, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 15 ft |
| Surface Area | 493 acres |
| Shoreline Length | 8.3 mi |
| Littoral Zone | 100% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Shell Lake
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 2015-09-08 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| White Sucker | 9.28 | 1.19 lb |
| Walleye | 6.28 | 1.84 lb |
| Northern Pike | 2.38 | 3.8 lb |
| Yellow Perch | 2.00 | 0.12 lb |
| Rock Bass | 0.33 | 0.27 lb |
| Bluegill | 0.33 | 0.23 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
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
Walleye
Northern Pike
Yellow Perch
From the 2015-09-08 survey
Shell Lake is located in the Boundary Waters Canoe Area Wilderness about 13 miles southeast of Crane Lake, MN. The lake is shallow; all 493 acres are less than 15 feet deep. The water is bog-stained and transparency was about 5 feet on September 10, 2015. Shoarelines are primarily ledge rock and boulder, though softer…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Shell Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — ShellFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +3.66 m/yr | 2 |
EPA Impairment Status
Shell 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 MN69-0461-00 · Official waterbody report
Graded lakes near Shell Lake
Shell Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in St. Louis County
Frequently asked questions about Shell Lake
What is the water quality grade for Shell Lake?
- Shell Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 9 ft visibility. Maximum depth: 15 ft. Surface area: 493.3 acres.
Is Shell Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Shell 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 Shell Lake?
- Shell Lake has a maximum depth of 15 feet. The lake covers 493.3 acres.
What fish are in Shell Lake?
- Fish species found in Shell Lake include bluegill, largemouth bass, northern pike, rock bass, smallmouth bass, walleye, white sucker, yellow perch. Shell Lake is located in St. Louis County, Minnesota.
Does Shell Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Shell Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (54,450 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Shell Lake across LakeGrade
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Where this data comes from
2 measurements from 2 monitoring stations, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA2 samples · 2024–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (2)
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