Roosevelt Lake
Roosevelt Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.1 ft visibility. Phosphorus: 12.5 µg/L. Chlorophyll-a (algae): 3.6 µg/L. Maximum depth: 129 ft. Surface area: 1510.58 acres.
- Clarity
- 11.1 ft
- Typical in August
- 76°F
- Max depth
- 129 ft
- Area
- 1,511 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 19
- Open water
- 235 days
Next lake in Cass County
Free interactive depth-contour map of Roosevelt Lake, reaching a maximum surveyed depth of 120 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Roosevelt Lake is a 1,511-acre mesotrophic lake in Cass County, Minnesota with a maximum depth of 129 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 18 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available. Compared to the 103 other monitored lakes in Cass County, Roosevelt Lake ranks #30 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-03. 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 11.1 ft. Phosphorus level: 12.5 µg/L. Chlorophyll-a: 3.6 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.1 ft | Not graded |
| Phosphorus | 12.5 µg/L | Good |
| Chlorophyll-a (Algae) | 3.6 µg/L | Good |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Roosevelt Lake
Compare lakeside cabins, hotels, and vacation rentals near Roosevelt 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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Water Temperature
Roosevelt Lake typically sits around 76°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 77°F) and coldest in May (about 62°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 23 field readings (2024–2025) via the EPA Water Quality Portal. See the full Roosevelt Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Roosevelt Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (97,275 cells/mL) on April 25, 2026.
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 | 129 ft |
| Surface Area | 1,511 acres |
| Shoreline Length | 18.6 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 Roosevelt 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
17 surveys on file from MN DNR Fisheries. Most recent: 2024-07-08 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluntnose Minnow | 91.05 | — |
| Bluegill | 39.49 | 0.11 lb |
| Yellow Perch | 19.60 | 0.13 lb |
| Largemouth Bass | 16.64 | 0.82 lb |
| Tullibee (Cisco) | 14.56 | 0.34 lb |
| BKF | 9.70 | — |
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
Largemouth Bass
Tullibee (Cisco)
From the 2024-07-08 survey
Roosevelt is a 1,511 acre lake located in the town of Outing in Cass County. It has a maximum depth of 129 feet and 25% of the lake is 15 feet deep or less. On the east side of the lake is a DNR access one mile south of Outing on the west side of Minnesota Highway 6. Muskellunge are the primary managed species on…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Roosevelt Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — RooseveltFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Roosevelt (1487)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — RooseveltFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — RooseveltPublic 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 | +0.072 m/yr | 6 |
| Phosphorus | ↑ Improving | -0.39 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.15 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (41 observations).
Estimated open water season: 235 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2021-04-06 (2021) | 2022-05-07 (2022) |
| Ice-In | 2018-11-28 (2018) | 2006-12-21 (2006) |
Most recent ice-out: 2025-04-16
Reservoir Info (USACE NID)
Roosevelt Lake is a man-made reservoir impounded by the Roosevelt Lake (completed 1936), built primarily for recreation on the Crooked Creek; gravity-type dam, 8 ft tall and 41 ft long.
- Surface area
- 1,510 ac
- Normal storage
- 67,360 ac-ft
- Max storage
- 72,412 ac-ft
- Drainage area
- 40 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN00051 · Operator website
EPA Impairment Status
Roosevelt 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 MN11-0043-02 · Official waterbody report · Matched by proximity (0.68 km)
County Ranking
Ranked #30 of 104 lakes in Cass County
Nearby Lakes in Cass County
Frequently asked questions about Roosevelt Lake
What is the water quality grade for Roosevelt Lake?
- Roosevelt Lake in Cass County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.1 ft visibility. Phosphorus: 12.5 µg/L. Chlorophyll-a (algae): 3.6 µg/L. Maximum depth: 129 ft. Surface area: 1510.58 acres.
Is Roosevelt Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Roosevelt Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Roosevelt Lake?
- Roosevelt Lake typically sits around 76°F at the surface in August, from 23 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Roosevelt Lake?
- Roosevelt Lake has a maximum depth of 129 feet. The lake covers 1510.58 acres.
What fish are in Roosevelt Lake?
- Fish species found in Roosevelt Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, greater redhorse, green sunfish, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, rock bass, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Roosevelt Lake is located in Cass County, Minnesota.
When does Roosevelt Lake thaw?
- Roosevelt Lake typically has ice-out around Apr 19. Ice typically forms around Dec 10. The open water season is approximately 235 days.
Does Roosevelt Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Roosevelt Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (97,275 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Roosevelt Lake across LakeGrade
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Moderate nutrients, good water quality
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Where this data comes from
367 measurements from 6 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
MNPCA367 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (6)
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