Round Lake
Round Lake in Sawyer County, Wisconsin has a water quality grade of A (Excellent). Water clarity: 21.1 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 0.9 µg/L. Maximum depth: 74 ft. Surface area: 3294 acres.
- Clarity
- 21.1 ft
- Max depth
- 74 ft
- Area
- 3,294 acres
- Type
- Oligotrophic
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Sawyer County
Round Lake is a 3,294-acre cold, clear oligotrophic lake in Sawyer County, Wisconsin with a maximum depth of 74 feet. Water quality is graded A based on 2 sampling years through 2026. Overall water quality is improving over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 2 public boat landings. Compared to the 44 other monitored lakes in Sawyer County, Round Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-07-06. Grade methodology: LakeGrade methodology.
Watch Round Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
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 21.1 ft down. Phosphorus level: 14 µg/L. Chlorophyll-a: 0.9 µg/L. Trophic State Index: 35.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 21.1 ft | Not graded |
| Phosphorus | 14 µg/L | Good |
| Chlorophyll-a (Algae) | 0.9 µg/L | Good |
| Trophic State Index (TSI) | 35 | 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 Sawyer County, Wisconsin — 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
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 trip? Cabins and lodging at Round Lake → · more Wisconsin lake trips
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 moderate (22,491 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 | 74 ft |
| Surface Area | 3,294 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Round LakePublic
- Round LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Round 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.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1995. 11 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Round Lake covering fish populations, stocking, water quality, and management. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2025Round Lake spring survey, 2025Fisheries Survey · WI DNR · 2025 (PDF)
- 2023Round Lake spring shocking and netting survey, 2023Spring Shocking Survey · WI DNR · 2023 (PDF)
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.482 m/yr | 7 |
| Phosphorus | ↓ Declining | +1 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.05 µg/L/yr | 5 |
County Ranking
Ranked #3 of 45 lakes in Sawyer County
Nearby Lakes in Sawyer County
Frequently asked questions about Round Lake
What is the water quality grade for Round Lake?
- Round Lake in Sawyer County, Wisconsin has a water quality grade of A (Excellent). Water clarity: 21.1 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 0.9 µg/L. Maximum depth: 74 ft. Surface area: 3294 acres.
Is Round Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Round Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 0.9 µg/L. Always check local health department advisories before swimming.
How deep is Round Lake?
- Round Lake has a maximum depth of 74 feet. The lake covers 3294 acres.
What fish are in Round Lake?
- Fish species found in Round Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Round Lake is located in Sawyer County, Wisconsin.
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 moderate (22,491 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Round Lake?
- Round Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Round Lake, Round Lake. Public access is listed as yes.
Explore Round Lake across LakeGrade
Fish species and top-graded lakes across Wisconsin
Fish species and best lakes in Sawyer County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Hayward Lakes area
Where to stay at Wisconsin's top lakes, each with its grade
Lakes in the Chippewa River Watershed, ranked by water quality
Low nutrients, clear water, excellent for swimming
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
Other Grade A Lakes in Wisconsin
Oligotrophic Lakes in Wisconsin
Compare Round Lake With Nearby Lakes
Where this data comes from
320 measurements from 7 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Lac Courte Oreilles (Tribal)
LCOWIS_WQX221 samples · 2020–2024 - Wisconsin Department of Natural Resources
WIDNR_WQX99 samples · 2020–2026
Analytical methods
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 4500 P F ~ Phosphorus in Water by Colorimetry Automated Ascorbic Acid Method
- 2320 B ~ Alkalinity by Gran Titration
- 4500 P E ~ Phosphorus by Ascorbic Acid
- 10200 H ~ Chlorophyll a-b-c Determination
- Total Phosphorus After Block Digestion
- Phosphorus by Colorimetry
Monitoring station identifiers (7)
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)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory