Dumbbell Lake
Dumbbell Lake in Lake County, Minnesota has a water quality grade of A (Excellent). Water clarity: 14.8 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 40 ft. Surface area: 406.11 acres.
- Clarity
- 14.8 ft
- Typical in August
- 65°F
- Max depth
- 40 ft
- Area
- 406 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- May 1
Next lake in Lake County
Dumbbell Lake is a 406-acre mesotrophic lake in Lake County, Minnesota with a maximum depth of 40 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 6 documented fish species including muskellunge, rock bass, and smallmouth bass. Public access is available with 1 public boat landing. Compared to the 34 other monitored lakes in Lake County, Dumbbell Lake ranks #7 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-26. Grade methodology: LakeGrade methodology.
Watch Dumbbell Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyLimited data
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 14.8 ft. Phosphorus level: 13.5 µg/L. Chlorophyll-a: 4 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.8 ft | Not graded |
| Phosphorus | 13.5 µg/L | Good |
| Chlorophyll-a (Algae) | 4 µg/L | Good |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Dumbbell Lake
Compare lakeside cabins, hotels, and vacation rentals near Dumbbell Lake in Lake 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 Dumbbell Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Dumbbell Lake typically sits around 65°F at the surface in August. Summer average is about 62°F. Usually warmest in Aug (about 65°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 124 field readings (2017–2025) via the EPA Water Quality Portal. See the full Dumbbell Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 40 ft |
| Surface Area | 406 acres |
| Shoreline Length | 8.9 mi |
| Littoral Zone | 50% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Dumbbell LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Dumbbell Lake
DNR Fisheries Survey Summary
22 surveys on file from MN DNR Fisheries. Most recent: 2023-08-07 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| BNS | 21.12 | — |
| Yellow Perch | 12.56 | 0.12 lb |
| Walleye | 8.02 | 1.53 lb |
| White Sucker | 7.48 | 0.9 lb |
| Rock Bass | 4.49 | 0.23 lb |
| Smallmouth Bass | 2.91 | 0.31 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.
Yellow Perch
Walleye
White Sucker
Rock Bass
From the 2023-08-07 survey
Dumbbell Lake is in Lake County about six miles east of Isabella and within the Superior National Forest. There is a public access with concrete log boat ramp and dock with parking for several trailer rigs located on Forest Service Road 172. There is also a picnic area with airplane dock and fishing pier located…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Dumbbell Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — DumbbellFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Dumbbell (0982)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — DumbbellFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — DumbbellPublic 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 | → Stable | +0.047 m/yr | 6 |
| Phosphorus | ↑ Improving | -10 µg/L/yr | 2 |
Ice Season
Historical ice data from Minnesota DNR (6 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 1998-04-23 (1998) | 2004-05-05 (2004) |
Most recent ice-out: 2020-05-04
EPA Impairment Status
Dumbbell Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN38-0393-00 · Official waterbody report
County Ranking
Ranked #7 of 35 lakes in Lake County
Nearby Lakes in Lake County
Frequently asked questions about Dumbbell Lake
What is the water quality grade for Dumbbell Lake?
- Dumbbell Lake in Lake County, Minnesota has a water quality grade of A (Excellent). Water clarity: 14.8 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 40 ft. Surface area: 406.11 acres.
Is Dumbbell Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Dumbbell Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Dumbbell Lake?
- Dumbbell Lake typically sits around 65°F at the surface in August, from 124 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
How deep is Dumbbell Lake?
- Dumbbell Lake has a maximum depth of 40 feet. The lake covers 406.11 acres.
What fish are in Dumbbell Lake?
- Fish species found in Dumbbell Lake include muskellunge, rock bass, smallmouth bass, walleye, white sucker, yellow perch. Dumbbell Lake is located in Lake County, Minnesota.
When does Dumbbell Lake thaw?
- Dumbbell Lake typically has ice-out around May 1.
Are there boat ramps on Dumbbell Lake?
- Dumbbell Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Dumbbell Lake. Public access is listed as yes.
Explore Dumbbell Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Lake County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Moderate nutrients, good water quality
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Dumbbell Lake
Other Grade A Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
50 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
MNPCA50 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
Impairment status from EPA ATTAINS 303(d) database
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