Big Pine Lake
Big Pine Lake in Aitkin County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 1.6 µg/L. Maximum depth: 78 ft. Surface area: 638.02 acres.
- Clarity
- 17 ft
- Typical in August
- 74°F
- Max depth
- 78 ft
- Area
- 638 acres
- Type
- Oligotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 15
- Open water
- 233 days
Next lake in Aitkin County
Big Pine Lake is a 638-acre cold, clear oligotrophic lake in Aitkin County, Minnesota with a maximum depth of 78 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 15 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 17 other monitored lakes in Aitkin County, Big Pine Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-03. Grade methodology: LakeGrade methodology.
Watch Big Pine Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyLow algae
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Crystal clear, you can see 17 ft down. Phosphorus level: 15 µg/L. Chlorophyll-a: 1.6 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 17 ft | Not graded |
| Phosphorus | 15 µg/L | Good |
| Chlorophyll-a (Algae) | 1.6 µg/L | Good |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Big Pine Lake
Compare lakeside cabins, hotels, and vacation rentals near Big Pine Lake in Aitkin 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 Big Pine Lake
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 →
Water Temperature
Big Pine Lake typically sits around 74°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 75°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 54 field readings (2016–2025) via the EPA Water Quality Portal. See the full Big Pine Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Big Pine Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (6,486 cells/mL) on November 21, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 78 ft |
| Surface Area | 638 acres |
| Shoreline Length | 6.4 mi |
| Littoral Zone | 41% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Big Pine LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Big Pine Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2024-08-26 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluntnose Minnow | 25.44 | — |
| Bluegill | 11.88 | 0.13 lb |
| SUN | 10.22 | — |
| Largemouth Bass | 9.29 | 0.6 lb |
| JND | 8.80 | — |
| CNM | 8.38 | — |
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
From the 2024-08-26 survey
Big Pine Lake is a moderately clear water lake located in southwestern Aitkin County and is part of the Mille Lacs/Rum River watershed. There is a state-owned public access located on the south side of the lake. Big Pine Lake has a variety of habitats available to the angler from open, wind-swept gravel and rock to…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Big Pine Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Big PineFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Big Pine (0033)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Big PineFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Big PinePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.305 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.45 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -1.14 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (11 observations).
Estimated open water season: 233 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-16 (2024) | 2023-05-03 (2023) |
| Ice-In | 2002-11-20 (2002) | 2024-12-11 (2024) |
Most recent ice-out: 2025-04-14
EPA Impairment Status
Big Pine Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN01-0157-00 · Official waterbody report
County Ranking
Ranked #4 of 18 lakes in Aitkin County
Nearby Lakes in Aitkin County
Frequently asked questions about Big Pine Lake
What is the water quality grade for Big Pine Lake?
- Big Pine Lake in Aitkin County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 1.6 µg/L. Maximum depth: 78 ft. Surface area: 638.02 acres.
Is Big Pine Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Big Pine Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 1.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Big Pine Lake?
- Big Pine Lake typically sits around 74°F at the surface in August, from 54 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
How deep is Big Pine Lake?
- Big Pine Lake has a maximum depth of 78 feet. The lake covers 638.02 acres.
What fish are in Big Pine Lake?
- Fish species found in Big Pine Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, yellow bullhead, yellow perch. Big Pine Lake is located in Aitkin County, Minnesota.
When does Big Pine Lake thaw?
- Big Pine Lake typically has ice-out around Apr 15. Ice typically forms around Dec 4. The open water season is approximately 233 days.
Does Big Pine Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Big Pine Lake (clouds, ice, or an off-season gap). The most recent reading was low (6,486 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Big Pine Lake?
- Big Pine Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Big Pine Lake. Public access is listed as yes.
Explore Big Pine Lake across LakeGrade
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Aitkin County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Brainerd Lakes area
Top lakes and where to stay in the Mille Lacs Area area
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Rum River Watershed, ranked by water quality
Lakes in the Pine River Watersheds (Brainerd Lakes), ranked by water quality
Low nutrients, clear water, excellent for swimming
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Big Pine Lake
Other Grade A Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Compare Big Pine Lake With Nearby Lakes
Where this data comes from
186 measurements from 4 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA186 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (4)
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
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate