Lake Winnibigoshish
Lake Winnibigoshish in Cass County, Minnesota has a water quality grade of C (Fair). Water clarity: 12.1 ft visibility. Phosphorus: 29 µg/L. Chlorophyll-a (algae): 5.2 µg/L. Maximum depth: 69.8 ft. Surface area: 56471.4 acres.
- Clarity
- 12.1 ft
- Typical in August
- 69°F
- Max depth
- 69.8 ft
- Area
- 56,471 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 27
Next lake in Cass County
Free interactive depth-contour map of Lake Winnibigoshish, reaching a maximum surveyed depth of 70 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Lake Winnibigoshish is a 56,471-acre mesotrophic lake in Cass County, Minnesota with a maximum depth of 70 feet (15-foot average). Water quality is graded C based on 3 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 20 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings. Compared to the 103 other monitored lakes in Cass County, Lake Winnibigoshish ranks #98 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-14. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Good clarity, visible to about 12.1 ft. Phosphorus level: 29 µg/L. Chlorophyll-a: 5.2 µg/L. Trophic State Index: 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.1 ft | Not graded |
| Phosphorus | 29 µg/L | Fair |
| Chlorophyll-a (Algae) | 5.2 µg/L | Good |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Lake Winnibigoshish
Compare lakeside cabins, hotels, and vacation rentals near Lake Winnibigoshish in Cass 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 Lake Winnibigoshish
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Water Temperature
Lake Winnibigoshish typically sits around 69°F at the surface in August. Summer average is about 66°F. Usually warmest in Jul (about 69°F) and coldest in May (about 49°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 240 field readings (2024–2025) via the EPA Water Quality Portal. See the full Lake Winnibigoshish water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 69.8 ft |
| Average Depth | 15.1 ft |
| Surface Area | 56,471 acres |
| Shoreline Length | 69.8 mi |
| Littoral Zone | 33% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Richards TownsitePublic
- Nodak Lodge and ResortSemi-private
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Lake Winnibigoshish
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
38 surveys on file from MN DNR Fisheries. Most recent: 2024-05-16 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Yellow Perch | 227.14 | 0.19 lb |
| Spottail Shiner | 109.89 | — |
| MMS | 75.59 | — |
| Bluntnose Minnow | 22.18 | — |
| Walleye | 20.75 | 1.18 lb |
| SUN | 13.15 | — |
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.
Yellow Perch
Walleye
From the 2024-05-16 survey
Lake Winnibigoshish, otherwise known as Winnie or Big Winnie, is a large reservoir located immediately north of the community of Bena, Minnesota. Winnie was a natural lake that was impounded in the 1880's with a dam controlled by the U.S. Army Corps of Engineers (USACE). Today the USACE maintains water levels within a…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Lake Winnibigoshish. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — WinnibigoshishFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Winnibigoshish (0702)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — WinnibigoshishFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — WinnibigoshishPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -1.17 m/yr | 2 |
| Phosphorus | ↑ Improving | -2.5 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -0.2 µg/L/yr | 2 |
Ice Season
Historical ice data from Minnesota DNR (32 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-30 (2012) | 2013-05-17 (2013) |
| Ice-In | 2023-11-29 (2023) | 2019-12-02 (2019) |
Most recent ice-out: 2025-04-29
Reservoir Info (USACE NID)
Lake Winnibigoshish is a man-made reservoir impounded by the Winnibigoshish Dam - Dike 1 (completed 1884), built primarily for water supply on the MISSISSIPPI RIVER; earth-type dam, 5 ft tall and 50 ft long.
- Surface area
- 68,000 ac
- Normal storage
- 220,000 ac-ft
- Max storage
- 550,000 ac-ft
- Drainage area
- 1,442 sq mi
- Hazard class
- Significant
- Owner
- USACE - St. Paul District
All listed purposes: Water Supply;Navigation;Fish and Wildlife Pond;Recreation;Flood Risk Reduction.
Source: USACE National Inventory of Dams, NID ID MN00586 · Operator website
County Ranking
Ranked #98 of 104 lakes in Cass County
Nearby Lakes With Higher Grades
Lake Winnibigoshish holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Cass County
Frequently asked questions about Lake Winnibigoshish
What is the water quality grade for Lake Winnibigoshish?
- Lake Winnibigoshish in Cass County, Minnesota has a water quality grade of C (Fair). Water clarity: 12.1 ft visibility. Phosphorus: 29 µg/L. Chlorophyll-a (algae): 5.2 µg/L. Maximum depth: 69.8 ft. Surface area: 56471.4 acres.
Is Lake Winnibigoshish safe to swim in?
- Generally safe for swimming, moderate water quality. Lake Winnibigoshish has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 5.2 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Lake Winnibigoshish?
- Lake Winnibigoshish typically sits around 69°F at the surface in August, from 240 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Lake Winnibigoshish?
- Lake Winnibigoshish has a maximum depth of 69.8 feet and an average depth of 15.1 feet. The lake covers 56471.4 acres.
What fish are in Lake Winnibigoshish?
- Fish species found in Lake Winnibigoshish include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, burbot, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, rock bass, shorthead redhorse, silver redhorse, sunfish, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Lake Winnibigoshish is located in Cass County, Minnesota.
When does Lake Winnibigoshish thaw?
- Lake Winnibigoshish typically has ice-out around Apr 27.
Are there boat ramps on Lake Winnibigoshish?
- Lake Winnibigoshish has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Richards Townsite, Nodak Lodge and Resort. Public access is listed as yes.
Explore Lake Winnibigoshish across LakeGrade
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Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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Where this data comes from
46 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Leech Lake Band of Ojibwe
LEECHLAK_WQX46 samples · 2024–2025
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Nitrate-Nitrite Nitrogen by Colorimetry
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