Wolf Lake
St. Louis County, MinnesotaLimited DataEutrophic
On the LakeGrade rubric Wolf Lake fails the cutoffs — a TSI of 67 and persistent algal pressure put it in the bottom tier.
At a TSI of 67, Wolf Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of just 12 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. Wolf Lake covers 456 acres alongside 10.1 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 187 graded lakes of St. Louis County, Wolf Lake sits at rank 181, near the bottom of the county list.
No invasive species are currently listed at Wolf Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at Wolf Lake, one of 8 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-10-10. Grade methodology: LakeGrade methodology.
Track Wolf Lake
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 2 ft of visibility. Trophic State Index: 67.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 67 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 12 ft |
| Average Depth | 5 ft |
| Surface Area | 455.63 acres |
| Shoreline Length | 10.1 mi |
| Littoral Zone | 100% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Wolf Lake (14-day solunar calendar)
→ Is it safe to eat fish from Wolf Lake? (mercury & PFAS guide)
→ Wolf Lake fishing regulations (limits, seasons, special rules)
Location
County Ranking
Ranked #181 of 187 lakes in St. Louis County
Cleaner Lakes Within 30 Miles
Wolf Lake holds Grade F. 2 nearby lakes hold higher grades.
Nearby Lakes in St. Louis County
More Minnesota Lake Rankings
State Parks Near Wolf Lake
Other Grade F Lakes in Minnesota
Eutrophic Lakes in Minnesota
Compare Wolf Lake With Nearby Lakes
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2018-08-13 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| White Sucker | 6.47 | 2.12 lb |
| Yellow Perch | 2.44 | 0.18 lb |
| Black Crappie | 2.25 | 0.42 lb |
| Walleye | 1.88 | 2.17 lb |
| Pumpkinseed | 1.27 | 0.2 lb |
| Northern Pike | 1.19 | 1.87 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
Yellow Perch
Black Crappie
Walleye
From the 2018-08-13 survey
Wolf Lake is a shallow, man-made reservoir located 15 miles northwest of Two Harbors, Minnesota. Wolf Lake is 456 acres, has a maximum depth of 12 feet, and is in lake class 12. The lake lies within both the Superior National Forest and the Cloquet Valley State Forest and is accessible by a public access at the south…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Wolf Lake. 3 reports on file.
- —Fisheries Lake Survey — WolfFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Wolf (1029)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — WolfPublic Water Access Sites · MN DNR LakeFinder
Reservoir Info (USACE NID)
Wolf Lake is a man-made reservoir impounded by the Wolf Lake (completed 1941), built primarily for recreation on the Wolf Creek; gravity-type dam, 16 ft tall and 68 ft long.
- Surface area
- 467 ac
- Normal storage
- 2,102 ac-ft
- Max storage
- 3,503 ac-ft
- Drainage area
- 32.9 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN00003 · Operator website
EPA Impairment Status
Wolf 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 MN69-0143-00 · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2022-10-10
Monitoring stations: 1