Jacobs Lake
St. Louis County, Minnesota90 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Jacobs Lake. Here is what has been measured.
- 9 ft max depth
- Public access
- Limited data
Jacobs Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4.5 ft visibility. Maximum depth: 9 ft. Surface area: 89.8 acres.
Minnesota DNR's Standard Survey on June 18, 2008 caught 13.00 northern pike per gill net at Jacobs Lake. DNR survey details →
Jacobs Lake is a 90-acre lake in St. Louis County, Minnesota with a maximum depth of 9 feet (4-foot average). Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-09-06. Methodology: how these readings are compared.
What Jacobs Lake is good for
From access and monitoring records, not editorial picks.
- Ice seasonIce-out around Apr 29
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Jacobs Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Jacobs Lake
These are the measurements Minnesota PCA publishes for Jacobs Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 4.5 ft. TSI 55.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 55 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Jacobs Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on June 18, 2008 caught 13.00 northern pike per gill net at Jacobs Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Jacobs Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 2008-06-18 (Standard Survey).
2 surveys on file · most recent 2008-06-18 (Standard Survey)
18 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 233.11 | 4–13 in 2008-06-18 | 0.3 lb |
| Yellow Perch | 67.08 | 6–8 in 2008-06-18 | 0.18 lb |
| Bluegill | 38.95 | 5–7 in 2008-06-18 | 0.27 lb |
| Black Crappie | 10.72 | 8–9 in 2008-06-18 | 0.33 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Bluegill
Black Crappie
From the 2008-06-18 survey
Jacobs is an 88-acre lake with 88 acres (100%) of littoral area and a maximum depth of 9 feet. The lake is heavily vegetated and located 9 miles north of Duluth, Minnesota. There is no public access to Jacobs Lake. Jacobs was initially surveyed in 1964 and again in 1997 by DNR fisheries. A population assessment was…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Jacobs Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — JacobsFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Jacobs (0465)Aquatic Plant Report · MN DNR LakeFinder
Lake Details
Max depth
9 ft
Average depth
4 ft
Surface area
90 acres
Shoreline
2.6 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
3 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,365 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Jacobs Lake
Compare lakeside cabins, hotels, and vacation rentals near Jacobs 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 Jacobs Lake
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Fishing Jacobs Lake
Water Quality Trend: Improving
Based on 4 years of monitoring (2020–2024).
Water clarity
Improving4 years
Ice season
Typical ice-out
Apr 29
Earliest Mar 14, 2024 · Latest May 7, 2022
Typical ice-in
Nov 21
Earliest Nov 2, 2019 · Latest Dec 2, 2009
Most recent ice-out
Mar 14
2024
32 observations · Minnesota PCA ice records
Nearby Lakes in St. Louis County
Frequently asked questions about Jacobs Lake
Where is Jacobs Lake?
- Jacobs Lake is a lake in St. Louis County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Jacobs Lake?
- Jacobs Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4.5 ft visibility. Maximum depth: 9 ft. Surface area: 89.8 acres.
Is Jacobs Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Jacobs Lake?
- Jacobs Lake has a maximum depth of 9 feet and an average depth of 4 feet. The lake covers 89.8 acres.
What did the DNR fisheries survey find at Jacobs Lake?
- Minnesota DNR's Standard Survey on June 18, 2008 caught 13.00 northern pike per gill net at Jacobs Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Jacobs Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Jacobs Lake thaw?
- Jacobs Lake typically has ice-out around Apr 29. Ice typically forms around Nov 21. The open water season is approximately 206 days.
Can I fish at Jacobs Lake?
- Public access to Jacobs Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Jacobs Lake across LakeQuality
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Where this data comes from
16 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA16 samples · 2020
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate