Rat Lake
Rat Lake in Itasca County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.3 ft visibility. Phosphorus: 62 µg/L. Chlorophyll-a (algae): 45.6 µg/L. Maximum depth: 20 ft. Surface area: 95.53 acres.
- Clarity
- 3.3 ft
- Max depth
- 20 ft
- Area
- 96 acres
- Public access
- Yes
Next lake in Itasca County
Why Rat Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Rat Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Rat Lake is a 96-acre lake in Itasca County, Minnesota with a maximum depth of 20 feet. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-07-14. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Rat Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Very murky, less than 3.3 ft of visibility. Phosphorus level: 62 µg/L. Chlorophyll-a: 45.6 µg/L. Trophic State Index: 64.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | Not graded |
| Phosphorus | 62 µg/L | Not graded |
| Chlorophyll-a (Algae) | 45.6 µg/L | Not graded |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Rat Lake
Compare lakeside cabins, hotels, and vacation rentals near Rat Lake in Itasca 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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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 20 ft |
| Surface Area | 96 acres |
| Shoreline Length | 1.9 mi |
| Littoral Zone | 73% |
| Public Access | Yes |
Recreation & Access
- Antler LakePublic
Fishing Rat Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1979-08-20 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 5.00 | 0.62 lb |
| Black Crappie | 4.00 | 0.25 lb |
| Northern Pike | 2.50 | 3.79 lb |
| Yellow Perch | 2.50 | 0.1 lb |
| Brown Bullhead | 2.00 | 1 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
From the 1979-08-20 survey
Fish population is within normal limits for this type of lake.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Rat Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — AnnFisheries Lake Survey · MN DNR LakeFinder
Graded lakes near Rat Lake
Rat Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Itasca County
Frequently asked questions about Rat Lake
What is the water quality grade for Rat Lake?
- Rat Lake in Itasca County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.3 ft visibility. Phosphorus: 62 µg/L. Chlorophyll-a (algae): 45.6 µg/L. Maximum depth: 20 ft. Surface area: 95.53 acres.
Is Rat Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Rat Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 45.6 µg/L. Always check local health department advisories before swimming.
How deep is Rat Lake?
- Rat Lake has a maximum depth of 20 feet. The lake covers 95.53 acres.
Are there boat ramps on Rat Lake?
- Rat Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Antler Lake. Public access is listed as yes.
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Where this data comes from
5 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA5 samples · 2022
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2130 B ~ Nephelometric Method
- 2120 B ~ Color in Water by Visual Comparison
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
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory