Hattie Lake
Hattie Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10.3 ft visibility. Phosphorus: 16.5 µg/L. Chlorophyll-a (algae): 4.5 µg/L. Maximum depth: 30 ft. Surface area: 587.82 acres.
- Clarity
- 10.3 ft
- Max depth
- 30 ft
- Area
- 588 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- No
Next lake in Cass County
Hattie Lake is a 588-acre mesotrophic lake in Cass County, Minnesota with a maximum depth of 30 feet (18-foot average). Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 14 documented fish species including black crappie, bluegill, and bowfin (dogfish). No public access — the lake is private or restricted. Compared to the 103 other monitored lakes in Cass County, Hattie Lake ranks #49 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-31. 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 10.3 ft. Phosphorus level: 16.5 µg/L. Chlorophyll-a: 4.5 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.3 ft | Not graded |
| Phosphorus | 16.5 µg/L | Good |
| Chlorophyll-a (Algae) | 4.5 µg/L | Good |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Hattie Lake
Compare lakeside cabins, hotels, and vacation rentals near Hattie Lake 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.
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 30 ft |
| Average Depth | 18 ft |
| Surface Area | 588 acres |
| Shoreline Length | 8.5 mi |
| Littoral Zone | 34% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Hattie Lake
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2002-06-17 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 18.98 | 0.21 lb |
| Yellow Perch | 13.22 | 0.15 lb |
| Yellow Bass | 6.34 | 0.55 lb |
| Pumpkinseed | 5.24 | 0.18 lb |
| Northern Pike | 4.01 | 1.71 lb |
| Tullibee (Cisco) | 2.23 | 1.02 lb |
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
Yellow Perch
Yellow Bass
Pumpkinseed
From the 2002-06-17 survey
Hattie Lake is 484-acre lake located near Backus, MN. With a maximum depth of 30 feet, app`roximately 41% of the surface area is littoral (less than 15 feet). There is no public access but it may be possible to access the lake through one of the resorts. The Minnesota Department of Natural Resources (MNDNR) has…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Hattie Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — HattieFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Hattie (1580)Aquatic Plant Report · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.07 m/yr | 5 |
| Phosphorus | → Stable | +0.2 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +0.16 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Hattie Lake is a man-made reservoir impounded by the Lake Hattie (completed 1937), built primarily for recreation on the Pine River; gravity-type dam, 10 ft tall and 55 ft long.
- Surface area
- 484 ac
- Normal storage
- 6,716 ac-ft
- Max storage
- 8,168 ac-ft
- Drainage area
- 85.3 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN00034 · Operator website
County Ranking
Ranked #49 of 104 lakes in Cass County
Nearby Lakes in Cass County
Frequently asked questions about Hattie Lake
What is the water quality grade for Hattie Lake?
- Hattie Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 10.3 ft visibility. Phosphorus: 16.5 µg/L. Chlorophyll-a (algae): 4.5 µg/L. Maximum depth: 30 ft. Surface area: 587.82 acres.
Is Hattie Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Hattie Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4.5 µg/L. Always check local health department advisories before swimming.
How deep is Hattie Lake?
- Hattie Lake has a maximum depth of 30 feet and an average depth of 18 feet. The lake covers 587.82 acres.
What fish are in Hattie Lake?
- Fish species found in Hattie Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, greater redhorse, largemouth bass, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Hattie Lake is located in Cass County, Minnesota.
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Moderate nutrients, good water quality
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Where this data comes from
44 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
MNPCA44 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