Spring Lake
St. Louis County, MinnesotaLimited DataMesotrophic
The LakeGrade rubric puts Spring Lake at a C: clarity at 9.5 ft, phosphorus readings still being added, and a TSI of 45 signal an intermediate trophic state.
Mesotrophic conditions dominate at Spring Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake bottoms out at 25 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake is compact at 98 acres, with 2.9 miles of shoreline and little volume to buffer nutrient inputs. Spring Lake sits at rank 107 of 187 in St. Louis County, in the lower half of the local distribution.
Spring Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Spring 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 2024-08-18. Grade methodology: LakeGrade methodology.
Track Spring Lake
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Moderate clarity, visible to about 9.5 ft. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9.5 ft | C |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 25 ft |
| Surface Area | 98.44 acres |
| Shoreline Length | 2.9 mi |
| Littoral Zone | 95% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Spring Lake (14-day solunar calendar)
→ Is it safe to eat fish from Spring Lake? (mercury & PFAS guide)
→ Spring Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.008 m/yr | 5 |
Location
County Ranking
Ranked #107 of 187 lakes in St. Louis County
Nearby Lakes in St. Louis County
More Minnesota Lake Rankings
Other Grade C Lakes in Minnesota
Mesotrophic Lakes in Minnesota
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2008-08-18 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 86.26 | 0.16 lb |
| Yellow Perch | 11.56 | 0.16 lb |
| TPM | 10.50 | — |
| White Sucker | 6.27 | 2.31 lb |
| Pumpkinseed | 4.89 | 0.12 lb |
| Northern Pike | 3.10 | 1.78 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.
Black Bullhead
Yellow Perch
White Sucker
Pumpkinseed
From the 2008-08-18 survey
Spring is a 97-acre lake with 93 acres (96%) of littoral area and a maximum depth of 25 feet. The lake is located 15 miles northeast of Duluth off highway #44 and has a concrete, back-in access. Parking at the access is very limited. Walleye fingerlings, yearlings or adults have been stocked in odd years since 1999.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Spring Lake. 3 reports on file.
- —Fisheries Lake Survey — SpringFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Spring (0492)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — SpringPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Spring 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 MN69-0130-00 · Official waterbody report · Matched by proximity (1.29 km)
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: 2024-08-18
Monitoring stations: 1