Big Lasalle Lake
Big Lasalle Lake in Clearwater County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10.2 ft visibility. Phosphorus: 10.5 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Maximum depth: 48 ft. Surface area: 235.22 acres.
- Clarity
- 10.2 ft
- Typical in August
- 61°F
- Max depth
- 48 ft
- Area
- 235 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 24
- Open water
- 208 days
Next lake in Clearwater County
Big Lasalle Lake is a 235-acre mesotrophic lake in Clearwater County, Minnesota with a maximum depth of 48 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 14 documented fish species including black crappie, bluegill, and brown bullhead. Public access is available with 1 public boat landing. Compared to the 36 other monitored lakes in Clearwater County, Big Lasalle Lake ranks #17 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-09. Grade methodology: LakeGrade methodology.
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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)
Good clarity, visible to about 10.2 ft. Phosphorus level: 10.5 µg/L. Chlorophyll-a: 3.2 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.2 ft | Not graded |
| Phosphorus | 10.5 µg/L | Good |
| Chlorophyll-a (Algae) | 3.2 µg/L | Good |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Big Lasalle Lake
Compare lakeside cabins, hotels, and vacation rentals near Big Lasalle Lake in Clearwater 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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Water Temperature
Big Lasalle Lake typically sits around 61°F at the surface in August. Summer average is about 59°F. Usually warmest in Aug (about 61°F) and coldest in Jun (about 57°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 417 field readings (2019–2025) via the EPA Water Quality Portal. See the full Big Lasalle Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 48 ft |
| Surface Area | 235 acres |
| Shoreline Length | 3.3 mi |
| Littoral Zone | 17% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Big LaSalle LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Big Lasalle Lake
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2023-07-31 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| MMS | 109.84 | — |
| Bluegill | 14.56 | 0.16 lb |
| Green Sunfish | 10.40 | 0.25 lb |
| CNM | 10.20 | — |
| IOD | 7.80 | — |
| Bluntnose Minnow | 7.34 | — |
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
Green Sunfish
From the 2023-07-31 survey
A temperature-dissolved oxygen profile was collected in the deepest basin on Big LaSalle Lake on July 31, 2023, to evaluate the amount of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee. Based on the profile, the top of the thermocline (i.e., the location in the water…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Big Lasalle 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 LaSalleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Big LaSalle (1317)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Big LaSalleFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Big LaSallePublic 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 | +0.437 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.29 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.34 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (14 observations).
Estimated open water season: 208 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 1992-04-15 (1992) | 1996-05-06 (1996) |
| Ice-In | 1991-11-07 (1991) | 1999-12-10 (1999) |
Most recent ice-out: 2018-05-01
County Ranking
Ranked #17 of 37 lakes in Clearwater County
Nearby Lakes in Clearwater County
Frequently asked questions about Big Lasalle Lake
What is the water quality grade for Big Lasalle Lake?
- Big Lasalle Lake in Clearwater County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10.2 ft visibility. Phosphorus: 10.5 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Maximum depth: 48 ft. Surface area: 235.22 acres.
Is Big Lasalle Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Big Lasalle Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.2 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Big Lasalle Lake?
- Big Lasalle Lake typically sits around 61°F at the surface in August, from 417 EPA Water Quality Portal field readings (2019–2025). That is a typical value for the month, not a live reading.
How deep is Big Lasalle Lake?
- Big Lasalle Lake has a maximum depth of 48 feet. The lake covers 235.22 acres.
What fish are in Big Lasalle Lake?
- Fish species found in Big Lasalle Lake include black crappie, bluegill, brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Big Lasalle Lake is located in Clearwater County, Minnesota.
When does Big Lasalle Lake thaw?
- Big Lasalle Lake typically has ice-out around Apr 24. Ice typically forms around Nov 18. The open water season is approximately 208 days.
Are there boat ramps on Big Lasalle Lake?
- Big Lasalle Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Big LaSalle Lake. Public access is listed as yes.
Explore Big Lasalle Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Clearwater County
Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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Other Grade A Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
85 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
MNPCA85 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)
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 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