Birch Lake
Cook County, Minnesota236 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Birch Lake. Here is what has been measured.
- Oligotrophic
- 69 ft max depth
- Public access
- Limited data
Birch Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 18 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 69 ft. Surface area: 236.31 acres.
Minnesota DNR's Standard Survey on August 21, 2023 caught 0.33 smallmouth bass per gill net at Birch Lake. DNR survey details →
Birch Lake is a 236-acre cold, clear oligotrophic lake in Cook County, Minnesota with a maximum depth of 69 feet (26-foot average). The lake supports 3 documented fish species including lake trout, rainbow trout, and smallmouth bass. Public access is available. Compared to the 43 other monitored lakes in Cook County, Birch Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-02. Methodology: how these readings are compared.
Birch Lake covers about 240 acres in Cook County. Vrbo is where to look for cabins and lake homes around Birch Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Birch Lake is good for
From access and monitoring records, not editorial picks.
- Clear water18 ft of visibility
- Fishing3 species recorded
- Deep water69 ft surveyed max depth
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Birch 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 Birch Lake
These are the measurements Minnesota PCA publishes for Birch Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 18 ft down. Phosphorus 8 µg/L. Chlorophyll-a 1.9 µg/L. TSI 35.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 18ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 8µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1.9µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 35 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Birch Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Birch Lake typically sits around 61°F at the surface in September. Summer average is about 63°F. Usually warmest in Jul (about 67°F) and coldest in May (about 48°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (48°F) to its warmest (67°F).
Typical surface water temperature by month, from 186 field readings (2016–2024) via the EPA Water Quality Portal. See the full Birch Lake water temperature breakdown →
Minnesota DNR's Standard Survey on August 21, 2023 caught 0.33 smallmouth bass per gill net at Birch Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Birch Lake’s water-quality measurements separately, and the water-quality trend over 5 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2023-08-21 (Standard Survey).
8 surveys on file · most recent 2023-08-21 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Fathead Minnow | 335.62 | ||
| White Sucker | 3.00 | 12–24 in 2015-09-08 | 1.89 lb |
| Rainbow Trout | 2.32 | 10–18 in 2023-08-21 | 1.47 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.
White Sucker
Rainbow Trout
From the 2023-08-21 survey
Birch Lake is a 236-acre lake located 34 miles north of Grand Marais and public access is through a carry-in access along the south shore. Rainbow trout are the primary management species with yearlings stocked every year since 2016. Brook trout were last stocked in 2015 and were not captured in the 2023 survey. In…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Birch Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — BirchFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — BirchFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — BirchPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
69 ft
Average depth
26 ft
Surface area
236 acres
Shoreline
6.7 mi
Littoral zone
30%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
3 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,775 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Birch Lake
Compare lakeside cabins, hotels, and vacation rentals near Birch Lake in Cook 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 Birch Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Birch Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Birch Lake
Water Quality Trend: Stable
Based on 5 years of monitoring (2020–2024).
Water clarity
Stable5 years
Nearby Lakes in Cook County
Frequently asked questions about Birch Lake
Where is Birch Lake?
- Birch Lake is a lake in Cook County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Birch Lake?
- Birch Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 18 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 69 ft. Surface area: 236.31 acres.
Is Birch Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Birch Lake?
- Birch Lake typically sits around 61°F at the surface in September, from 186 EPA Water Quality Portal field readings (2016–2024). That is a typical value for the month, not a live reading.
How deep is Birch Lake?
- Birch Lake has a maximum depth of 69 feet and an average depth of 26 feet. The lake covers 236.31 acres.
What fish are in Birch Lake?
- Fish species found in Birch Lake include lake trout, rainbow trout, smallmouth bass. Birch Lake is located in Cook County, Minnesota.
What did the DNR fisheries survey find at Birch Lake?
- Minnesota DNR's Standard Survey on August 21, 2023 caught 0.33 smallmouth bass per gill net at Birch Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Birch Lake’s water-quality measurements separately, and the water-quality trend over 5 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Birch Lake?
- Public access to Birch 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 Birch Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Cook County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Birch Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Where this data comes from
39 measurements from 2 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA39 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (2)
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