Blue Lake
Hubbard County, Minnesota336 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Blue Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- 84 ft max depth
- Public access
Blue Lake in Hubbard County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 17.3 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 84 ft. Surface area: 336.35 acres.
Minnesota DNR's Standard Survey on August 5, 2024 caught 13.78 walleye per gill net at Blue Lake. DNR survey details →
Blue Lake is a 336-acre cold, clear oligotrophic lake in Hubbard County, Minnesota with a maximum depth of 84 feet (44-foot average). Overall water quality is improving over recent sampling years. The lake supports 13 documented fish species including black crappie, bluegill, and brown bullhead. Public access is available with 1 public boat landing. Compared to the 67 other monitored lakes in Hubbard County, Blue Lake ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Methodology: how these readings are compared.
Blue Lake covers about 340 acres in Hubbard County. It has one public boat landing. The median ice-out date is April 26, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Blue Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Blue Lake is good for
From access and monitoring records, not editorial picks.
- Clear water17.3 ft of visibility
- Boat launch1 documented ramp
- Fishing13 species recorded
- Ice seasonIce-out around Apr 26
- Deep water84 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
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. Blue Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Blue 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 Blue Lake
These are the measurements Minnesota PCA publishes for Blue 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 17.3 ft down. Phosphorus 8 µg/L. Chlorophyll-a 1.9 µg/L. TSI 36.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 17.3ft | 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. | 36 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Blue Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Blue Lake typically sits around 65°F at the surface in September. Summer average is about 67°F. Usually warmest in Jul (about 74°F) and coldest in May (about 51°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (51°F) to its warmest (74°F).
Typical surface water temperature by month, from 89 field readings (2011–2025) via the EPA Water Quality Portal. See the full Blue Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Blue Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (10,375 cells/mL) on April 25, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on August 5, 2024 caught 13.78 walleye per gill net at Blue Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Blue Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
15 surveys on file from MN DNR Fisheries. Most recent: 2025-08-07 (Targeted Survey).
15 surveys on file · most recent 2025-08-07 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluntnose Minnow | 41.40 | ||
| Tullibee (Cisco) | 12.14 | 8–11 in 2024-08-05 | 0.28 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.
Tullibee (Cisco)
From the 2025-08-07 survey
Temperature and dissolved oxygen measurements were collected from the deepest basin in Blue Lake on August 7th, 2025. This was done to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Blue Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — BlueFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Blue (1276)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — BlueFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — BluePublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
84 ft
Average depth
44 ft
Surface area
336 acres
Shoreline
3.2 mi
Littoral zone
24%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
11 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,434 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Blue LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Blue Lake
Compare lakeside cabins, hotels, and vacation rentals near Blue Lake in Hubbard 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 Blue Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Blue Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Blue Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Worsening+0.23 µg/L/yr6 years
Chlorophyll-a
Improving-0.06 µg/L/yr6 years
Ice season
Typical ice-out
Apr 26
Earliest Mar 26, 2012 · Latest May 13, 2013
Typical ice-in
Dec 2
Earliest Nov 20, 2018 · Latest Dec 29, 2023
Most recent ice-out
Apr 5
2021
30 observations · Minnesota PCA ice records
EPA Impairment Status
Blue Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Fish consumption.
Source: EPA ATTAINS assessment unit MN29-0184-00 · Official waterbody report
Nearby Lakes in Hubbard County
Frequently asked questions about Blue Lake
Where is Blue Lake?
- Blue Lake is a lake in Hubbard County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Blue Lake?
- Blue Lake in Hubbard County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 17.3 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 84 ft. Surface area: 336.35 acres.
Is Blue Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Blue Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
What is the water temperature of Blue Lake?
- Blue Lake typically sits around 65°F at the surface in September, from 89 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Blue Lake?
- Blue Lake has a maximum depth of 84 feet and an average depth of 44 feet. The lake covers 336.35 acres.
What fish are in Blue Lake?
- Fish species found in Blue Lake include black crappie, bluegill, brown bullhead, largemouth bass, pumpkinseed, rainbow trout, rock bass, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Blue Lake is located in Hubbard County, Minnesota.
What did the DNR fisheries survey find at Blue Lake?
- Minnesota DNR's Standard Survey on August 5, 2024 caught 13.78 walleye per gill net at Blue Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Blue Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Blue Lake thaw?
- Blue Lake typically has ice-out around Apr 26. Ice typically forms around Dec 2. The open water season is approximately 220 days.
Does Blue Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Blue Lake (clouds, ice, or an off-season gap). The most recent reading was low (10,375 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Blue Lake?
- Blue Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Blue Lake. Public access is listed as yes.
Can I fish at Blue Lake?
- Blue Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. 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 Blue 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 Hubbard County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Park Rapids Area area
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Mississippi Headwaters, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Blue Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Where this data comes from
100 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA100 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate