Round Lake
Round Lake in Aitkin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.5 ft visibility. Maximum depth: 59 ft. Surface area: 634.03 acres.
- Clarity
- 14.5 ft
- Typical in August
- 62°F
- Max depth
- 59 ft
- Area
- 634 acres
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 19
- Open water
- 223 days
Next lake in Aitkin County
Why Round Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Round Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Round Lake is a 634-acre lake in Aitkin County, Minnesota with a maximum depth of 59 feet. Overall water quality is declining over recent sampling years. The lake supports 15 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-28. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Round Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 14.5 ft. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Round Lake
Compare lakeside cabins, hotels, and vacation rentals near Round Lake in Aitkin 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 Round Lake
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Water Temperature
Round Lake typically sits around 62°F at the surface in August. Summer average is about 62°F. Usually warmest in Jul (about 64°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 56 field readings (2016–2025) via the EPA Water Quality Portal.
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Round Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (147,231 cells/mL) on November 22, 2025.
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 | 59 ft |
| Surface Area | 634 acres |
| Shoreline Length | 3.7 mi |
| Littoral Zone | 75% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Round LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Round Lake
DNR Fisheries Survey Summary
27 surveys on file from MN DNR Fisheries. Most recent: 2025-09-09 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluntnose Minnow | 55.81 | — |
| Yellow Perch | 20.69 | 0.17 lb |
| Bluegill | 16.03 | 0.22 lb |
| Walleye | 15.80 | 1.35 lb |
| Spottail Shiner | 14.82 | — |
| JND | 8.57 | — |
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
Bluegill
Walleye
From the 2025-09-09 survey
Fall night electrofishing was conducted on 9/9/2025. Night electrofishing in the fall is a common method used to monitor the abundance of young-of-the-year (YOY) and yearling (age 1) Walleye. This survey is intended to provide information on Walleye survival and recruitment (both natural and from fry stocking) and…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Round Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — RoundFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Round (0147)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — RoundFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — RoundPublic 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 | ↓ Declining | -0.264 m/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (29 observations).
Estimated open water season: 223 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-24 (2012) | 2013-05-13 (2013) |
| Ice-In | 2014-11-15 (2014) | 2015-12-20 (2015) |
Most recent ice-out: 2020-04-18
EPA Impairment Status
Round 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 MN01-0137-00 · Official waterbody report
Graded lakes near Round Lake
Round Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Aitkin County
Frequently asked questions about Round Lake
What is the water quality grade for Round Lake?
- Round Lake in Aitkin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.5 ft visibility. Maximum depth: 59 ft. Surface area: 634.03 acres.
Is Round Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Round Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Round Lake?
- Round Lake typically sits around 62°F at the surface in August, from 56 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
How deep is Round Lake?
- Round Lake has a maximum depth of 59 feet. The lake covers 634.03 acres.
What fish are in Round Lake?
- Fish species found in Round Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, burbot, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow bullhead, yellow perch. Round Lake is located in Aitkin County, Minnesota.
When does Round Lake thaw?
- Round Lake typically has ice-out around Apr 19. Ice typically forms around Nov 28. The open water season is approximately 223 days.
Does Round Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Round Lake (clouds, ice, or an off-season gap). The most recent reading was high (147,231 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Round Lake?
- Round Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Round Lake. Public access is listed as yes.
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Where this data comes from
14 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
MNPCA14 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
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