Ten Mile Lake
Ten Mile Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 20.5 ft visibility. Phosphorus: 8.5 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 208 ft. Surface area: 5080.41 acres.
- Clarity
- 20.5 ft
- Typical in August
- 53°F
- Max depth
- 208 ft
- Area
- 5,080 acres
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 25
- Open water
- 230 days
Next lake in Cass County
Free interactive depth-contour map of Ten Mile Lake, reaching a maximum surveyed depth of 200 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Ten Mile Lake is a 5,080-acre cold, clear oligotrophic lake in Cass County, Minnesota with a maximum depth of 208 feet (52-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 17 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available. Compared to the 103 other monitored lakes in Cass County, Ten Mile Lake ranks #41 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-07. 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)
Crystal clear, you can see 20.5 ft down. Phosphorus level: 8.5 µg/L. Chlorophyll-a: 1.9 µg/L. Trophic State Index: 35.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 20.5 ft | Not graded |
| Phosphorus | 8.5 µg/L | Good |
| Chlorophyll-a (Algae) | 1.9 µg/L | Good |
| Trophic State Index (TSI) | 35 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Ten Mile Lake
Compare lakeside cabins, hotels, and vacation rentals near Ten Mile 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.
Top-rated places to stay near Ten Mile Lake
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Planning a trip? Cabins and lodging at Ten Mile Lake → · more Minnesota lake trips
Water Temperature
Ten Mile Lake typically sits around 53°F at the surface in August. Summer average is about 52°F. Usually warmest in Jul (about 53°F) and coldest in May (about 45°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 3,352 field readings (2010–2025) via the EPA Water Quality Portal. See the full Ten Mile Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 208 ft |
| Average Depth | 52.4 ft |
| Surface Area | 5,080 acres |
| Shoreline Length | 24.8 mi |
| Littoral Zone | 26% |
| Public Access | Yes |
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 Ten Mile 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
16 surveys on file from MN DNR Fisheries. Most recent: 2024-08-26 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluntnose Minnow | 21.47 | — |
| Bluegill | 14.49 | 0.15 lb |
| LND | 11.75 | — |
| JND | 10.28 | — |
| Rock Bass | 10.25 | 0.31 lb |
| BNS | 9.19 | — |
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
Rock Bass
From the 2024-08-26 survey
Ten Mile Lake is a 5,080-acre lake with 24.8 miles of shoreline and a maximum depth of 208 feet located north of Hackensack, MN. A Minnesota Department of Natural Resources (MNDNR) owned public access is located on the western shore. The DNR has classified Minnesota's lakes into 43 different classes based on physical,…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Ten Mile Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Ten MileFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Ten Mile (1461)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Ten MileFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Ten MilePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.112 m/yr | 6 |
| Phosphorus | → Stable | -0.09 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.09 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (91 observations).
Estimated open water season: 230 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-29 (2012) | 1996-05-18 (1996) |
| Ice-In | 1999-11-22 (1999) | 2003-01-02 (2003) |
Most recent ice-out: 2022-05-05
EPA Impairment Status
Ten Mile 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 MN11-0413-00 · Official waterbody report
County Ranking
Ranked #41 of 104 lakes in Cass County
Nearby Lakes in Cass County
Frequently asked questions about Ten Mile Lake
What is the water quality grade for Ten Mile Lake?
- Ten Mile Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 20.5 ft visibility. Phosphorus: 8.5 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 208 ft. Surface area: 5080.41 acres.
Is Ten Mile Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Ten Mile Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 1.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Ten Mile Lake?
- Ten Mile Lake typically sits around 53°F at the surface in August, from 3,352 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Ten Mile Lake?
- Ten Mile Lake has a maximum depth of 208 feet and an average depth of 52.4 feet. The lake covers 5080.41 acres.
What fish are in Ten Mile Lake?
- Fish species found in Ten Mile Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, cisco species, hybrid sunfish, lake whitefish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Ten Mile Lake is located in Cass County, Minnesota.
When does Ten Mile Lake thaw?
- Ten Mile Lake typically has ice-out around Apr 25. Ice typically forms around Dec 11. The open water season is approximately 230 days.
Explore Ten Mile Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Cass County
Species activity outlook by water temperature and season
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Where this data comes from
542 measurements from 9 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
MNPCA542 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (9)
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
Ice data from Minnesota DNR Climate