Susan Lake
Susan Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.6 ft visibility. Phosphorus: 32 µg/L. Chlorophyll-a (algae): 10.8 µg/L. Maximum depth: 10 ft. Surface area: 275.84 acres.
- Clarity
- 3.6 ft
- Max depth
- 10 ft
- Area
- 276 acres
- Public access
- Yes
Next lake in St. Louis County
Why Susan 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 Susan Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, 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.
Susan Lake is a 276-acre lake in St. Louis County, Minnesota with a maximum depth of 10 feet. The lake supports 7 documented fish species including black crappie, bluegill, and largemouth bass. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-07-21. 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 Susan Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Murky, only visible to about 3.6 ft. Phosphorus level: 32 µg/L. Chlorophyll-a: 10.8 µg/L. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.6 ft | Not graded |
| Phosphorus | 32 µg/L | Not graded |
| Chlorophyll-a (Algae) | 10.8 µg/L | Not graded |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Susan Lake
Compare lakeside cabins, hotels, and vacation rentals near Susan 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 Susan Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 10 ft |
| Surface Area | 276 acres |
| Shoreline Length | 5.1 mi |
| Littoral Zone | 100% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Elbow Lake (South)Public
- Head O' Lakes ResortPublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Susan Lake
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2025-08-25 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Yellow Perch | 7.25 | 0.42 lb |
| Walleye | 4.08 | 1.48 lb |
| Bluegill | 1.88 | 0.41 lb |
| Northern Pike | 1.45 | 1.57 lb |
| Pumpkinseed | 1.23 | 0.23 lb |
| White Sucker | 1.12 | 1.73 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.
Yellow Perch
Walleye
Bluegill
Northern Pike
From the 2025-08-25 survey
Susan Lake is located approximately four miles north of Wakemup, Minnesota. This 275-acre lake has a maximum depth of 10 feet and dark tannin-stained water. A fisheries survey was completed in Susan Lake during the 2025 field season as part of a regular rotation of surveys in the International Falls Management Area.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Susan Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — SusanFisheries Lake Survey · MN DNR LakeFinder
- —Public Water Access Sites — SusanPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Susan 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 MN69-0741-00 · Official waterbody report
Graded lakes near Susan Lake
Susan Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in St. Louis County
Frequently asked questions about Susan Lake
What is the water quality grade for Susan Lake?
- Susan Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.6 ft visibility. Phosphorus: 32 µg/L. Chlorophyll-a (algae): 10.8 µg/L. Maximum depth: 10 ft. Surface area: 275.84 acres.
Is Susan Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Susan Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 10.8 µg/L. Always check local health department advisories before swimming.
How deep is Susan Lake?
- Susan Lake has a maximum depth of 10 feet. The lake covers 275.84 acres.
What fish are in Susan Lake?
- Fish species found in Susan Lake include black crappie, bluegill, largemouth bass, northern pike, pumpkinseed, walleye, yellow perch. Susan Lake is located in St. Louis County, Minnesota.
Are there boat ramps on Susan Lake?
- Susan Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Elbow Lake (South), Head O' Lakes Resort. Public access is listed as yes.
Explore Susan Lake across LakeGrade
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Where this data comes from
5 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA5 samples · 2022
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2130 B ~ Nephelometric Method
- 2120 B ~ Color in Water by Visual Comparison
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
Named boat-access points from the USGS National Boat Ramps inventory