Fenske Lake
Fenske Lake in St. Louis County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.5 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 1.6 µg/L. Maximum depth: 43 ft. Surface area: 108.43 acres.
- Clarity
- 11.5 ft
- Typical in August
- 58°F
- Max depth
- 43 ft
- Area
- 108 acres
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- Yes
Next lake in St. Louis County
Fenske Lake is a 108-acre cold, clear oligotrophic lake in St. Louis County, Minnesota with a maximum depth of 43 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 8 documented fish species including black crappie, bluegill, and largemouth bass. Public access is available with 1 public boat landing. Compared to the 67 other monitored lakes in St. Louis County, Fenske Lake ranks #24 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-30. Grade methodology: LakeGrade methodology.
Watch Fenske Lake water quality
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 11.5 ft. Phosphorus level: 11 µg/L. Chlorophyll-a: 1.6 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | Not graded |
| Phosphorus | 11 µg/L | Good |
| Chlorophyll-a (Algae) | 1.6 µg/L | Good |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Fenske Lake
Compare lakeside cabins, hotels, and vacation rentals near Fenske 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.
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Water Temperature
Fenske Lake typically sits around 58°F at the surface in August. Summer average is about 56°F. Usually warmest in Aug (about 58°F) and coldest in Jun (about 52°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 69 field readings (2024–2025) via the EPA Water Quality Portal. See the full Fenske Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 43 ft |
| Surface Area | 108 acres |
| Shoreline Length | 4.6 mi |
| Littoral Zone | 58% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Fenske LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Fenske Lake
DNR Fisheries Survey Summary
6 surveys on file from MN DNR Fisheries. Most recent: 2017-07-24 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 9.87 | 0.17 lb |
| Tullibee (Cisco) | 2.03 | 0.53 lb |
| Northern Pike | 1.36 | 3.87 lb |
| White Sucker | 1.16 | 3.2 lb |
| Black Crappie | 1.04 | 0.5 lb |
| Largemouth Bass | 1.01 | 0.21 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.
Bluegill
Tullibee (Cisco)
Northern Pike
White Sucker
From the 2017-07-24 survey
Fenske Lake is located approximately 8 miles N of Ely within the Superior National Forest. There are several cabins around the lake and a small resort is located near the NW corner. The USFS operates a campround near the NW corner as well. There is a gravel boat ramp near the campground off CR 116 (Echo Trail) for…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Fenske Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — FenskeFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Fenske (1515)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — FenskePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.148 m/yr | 6 |
EPA Impairment Status
Fenske Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN69-0085-00 · Official waterbody report
County Ranking
Ranked #24 of 68 lakes in St. Louis County
Nearby Lakes in St. Louis County
Frequently asked questions about Fenske Lake
What is the water quality grade for Fenske Lake?
- Fenske Lake in St. Louis County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.5 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 1.6 µg/L. Maximum depth: 43 ft. Surface area: 108.43 acres.
Is Fenske Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Fenske Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 1.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Fenske Lake?
- Fenske Lake typically sits around 58°F at the surface in August, from 69 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Fenske Lake?
- Fenske Lake has a maximum depth of 43 feet. The lake covers 108.43 acres.
What fish are in Fenske Lake?
- Fish species found in Fenske Lake include black crappie, bluegill, largemouth bass, northern pike, smallmouth bass, tullibee (cisco), white sucker, yellow perch. Fenske Lake is located in St. Louis County, Minnesota.
Are there boat ramps on Fenske Lake?
- Fenske Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Fenske Lake. Public access is listed as yes.
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Where this data comes from
48 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
MNPCA48 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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