Rat Lake
Itasca County, Minnesota96 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Rat Lake. Here is what has been measured.
- 20 ft max depth
- Public access
- Limited data
Rat Lake in Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. 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.
Minnesota DNR's Standard Survey on August 20, 1979 caught 3.00 northern pike per gill net at Rat Lake. DNR survey details →
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.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-07-14. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Rat 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 Rat Lake
These are the measurements Minnesota PCA publishes for Rat Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 3.3 ft of visibility. Phosphorus 62 µg/L. Chlorophyll-a 45.6 µg/L. TSI 64.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 62µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 45.6µg/L | Measured, not scored 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. | 64 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Rat Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on August 20, 1979 caught 3.00 northern pike per gill net at Rat Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Rat Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1979-08-20 (Standard Survey).
1 survey on file · most recent 1979-08-20 (Standard Survey)
47 years old| Species | Catch rate (CPUE) | Size | 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, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Lake Details
Max depth
20 ft
Surface area
96 acres
Shoreline
1.9 mi
Littoral zone
73%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
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Fishing Rat Lake
Nearby Lakes in Itasca County
Frequently asked questions about Rat Lake
Where is Rat Lake?
- Rat Lake is a lake in Itasca County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Rat Lake?
- Rat Lake in Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. 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?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Rat Lake?
- Rat Lake has a maximum depth of 20 feet. The lake covers 95.53 acres.
What did the DNR fisheries survey find at Rat Lake?
- Minnesota DNR's Standard Survey on August 20, 1979 caught 3.00 northern pike per gill net at Rat Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Rat Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Rat Lake?
- Public access to Rat 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.
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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)
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 details from Minnesota DNR LakeFinder