Joe Martin Lake
Joe Martin Lake in St. Louis County, Minnesota has a water quality grade of C (Fair). Water clarity: 14.5 ft visibility. Phosphorus: 35.5 µg/L. Chlorophyll-a (algae): 2.3 µg/L. Maximum depth: 77 ft. Surface area: 67.8 acres.
- Clarity
- 14.5 ft
- Typical in August
- 64°F
- Max depth
- 77 ft
- Area
- 68 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- No
Next lake in St. Louis County
Joe Martin Lake is a 68-acre mesotrophic lake in St. Louis County, Minnesota with a maximum depth of 77 feet. Water quality is graded C based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. The lake supports 8 documented fish species including black crappie, bluegill, and hybrid sunfish. No public access — the lake is private or restricted. Compared to the 67 other monitored lakes in St. Louis County, Joe Martin Lake ranks #54 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-15. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Good clarity, visible to about 14.5 ft. Phosphorus level: 35.5 µg/L. Chlorophyll-a: 2.3 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.5 ft | Not graded |
| Phosphorus | 35.5 µg/L | Fair |
| Chlorophyll-a (Algae) | 2.3 µg/L | Good |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Joe Martin Lake
Compare lakeside cabins, hotels, and vacation rentals near Joe Martin 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
Joe Martin Lake typically sits around 64°F at the surface in August. Summer average is about 65°F. Usually warmest in Jul (about 76°F) and coldest in May (about 47°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 479 field readings (2010–2021) via the EPA Water Quality Portal. See the full Joe Martin Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 77 ft |
| Surface Area | 68 acres |
| Shoreline Length | 1.4 mi |
| Littoral Zone | 35% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Joe Martin Lake
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 2025-08-18 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 22.84 | 0.16 lb |
| CNM | 12.14 | — |
| Largemouth Bass | 8.45 | 0.7 lb |
| Pumpkinseed | 2.94 | 0.21 lb |
| Northern Pike | 2.48 | 1.42 lb |
| Black Crappie | 1.89 | 0.32 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
Largemouth Bass
Pumpkinseed
Northern Pike
From the 2025-08-18 survey
A targeted survey of nearshore fish species in Joe Martin Lake, which is located within Fond du Lac Band of Lake Superior Chippewa Nation, was conducted on August 18 - August 20, 2025 by Lake Biological Monitoring and Assessment (LBMA) Program and Fond du Lac Band of Ojibwe Natural Resources staff. Sampling sites were…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Joe Martin Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MartinFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Martin (0466)Aquatic Plant Report · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.624 m/yr | 5 |
| Phosphorus | ↓ Declining | +53.7 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -0.16 µg/L/yr | 5 |
EPA Impairment Status
Joe Martin Lake is officially listed as impaired under Clean Water Act §303(d) in the 2019 EPA reporting cycle.
Causes of impairment
Source: EPA ATTAINS assessment unit FDL_111 · Official waterbody report
County Ranking
Ranked #54 of 68 lakes in St. Louis County
Nearby Lakes With Higher Grades
Joe Martin Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in St. Louis County
Frequently asked questions about Joe Martin Lake
What is the water quality grade for Joe Martin Lake?
- Joe Martin Lake in St. Louis County, Minnesota has a water quality grade of C (Fair). Water clarity: 14.5 ft visibility. Phosphorus: 35.5 µg/L. Chlorophyll-a (algae): 2.3 µg/L. Maximum depth: 77 ft. Surface area: 67.8 acres.
Is Joe Martin Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Joe Martin Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 2.3 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Joe Martin Lake?
- Joe Martin Lake typically sits around 64°F at the surface in August, from 479 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
How deep is Joe Martin Lake?
- Joe Martin Lake has a maximum depth of 77 feet. The lake covers 67.8 acres.
What fish are in Joe Martin Lake?
- Fish species found in Joe Martin Lake include black crappie, bluegill, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, white sucker, yellow perch. Joe Martin Lake is located in St. Louis County, Minnesota.
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Where this data comes from
423 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Fond du Lac Band of Chippewa (MN)
FONDULAC_WQX423 samples · 2020–2024
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
- 10200 H ~ Chlorophyll a-b-c Determination
- Color, APHA Platinum-Cobalt
- For determination of Copper by the Bicinchoninate method.
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