Activities7 min readUpdated October 21, 2026

The Clearest Lakes in Northern Wisconsin

Ranked by decades of DNR water clarity readings, all within reach of our cabins

The Short Answer

Among lakes the Wisconsin DNR has monitored for decades, the clearest in northwest Wisconsin are Lake Owen (about 25 feet of visibility), Round Lake and Grindstone Lake near Hayward (21–22 feet), and Sand Lake in Burnett County (20 feet). Shell Lake, Lac Courte Oreilles, Whitefish Lake and Deer Lake all run 13–16 feet. Visibility is the long-term summer average measured with a Secchi disk; on a calm July morning most of these lakes look clearer still.

How This List Was Built

Most "clearest lakes" lists are one person's opinion. This one is built from the Wisconsin DNR's Citizen Lake Monitoring Network, where volunteers have lowered a black-and-white Secchi disk into the same spot on the same lakes every summer, some of them since the 1970s. The depth at which the disk disappears is the clarity reading. We pulled every monitored lake over 100 acres in the counties around our cabins and ranked them by their long-term July–August average.

A few things to know about the numbers. They are averages over decades, not a single best day, so a lake listed at 13 feet will often show you the bottom at 15 or more in early summer before the algae season. Lakes with fewer than ten readings are left off. And a handful of excellent lakes have no volunteer and no data; if you know one, tell us and we'll add it with a note.

As a rough guide: under 7 feet is typical for a fertile, weedy lake; 10 feet is clear; anything over 15 feet is rare in Wisconsin and feels like a different kind of water.

The Clearest Lakes Near Our Cabins

Long-term DNR summer averages. Tap a lake for landings, fish, depth and nearby cabins.

Round Lake

Sawyer County

Full guide →

3,294 acres74 ft deep3 landings21.0 ft clarity

Fish Species

Largemouth Bass· AbundantMuskyNorthern PikePanfish· CommonSmallmouth Bass· AbundantWalleye· Abundant

Grindstone Lake

Sawyer County

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3,176 acres60 ft deep2 landings20.7 ft clarity

Fish Species

Largemouth BassMusky· CommonNorthern Pike· CommonPanfishSmallmouth Bass· CommonWalleye· Abundant

Sand Lake

Burnett County

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900 acres73 ft deep1 landing

Fish Species

Largemouth Bass· CommonNorthern Pike· AbundantPanfishWalleye· Common

Lac Courte Oreilles

Sawyer County

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5,139 acres90 ft deep3 landings14.9 ft clarity

Fish Species

Largemouth BassMusky· CommonNorthern Pike· AbundantPanfish· CommonSmallmouth Bass· CommonWalleye· Common

Shell Lake

Washburn County

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2,513 acres36 ft deep5 landings13.2 ft clarity

Fish Species

Largemouth BassMusky· CommonNorthern PikePanfish· CommonSmallmouth Bass· AbundantWalleye· Abundant

Whitefish Lake

Sawyer County

Full guide →

800 acres105 ft deep1 landing13.2 ft clarity

Fish Species

Largemouth Bass· CommonMusky· CommonNorthern Pike· AbundantPanfishSmallmouth Bass· CommonTrout

The Ranking

Lake Owen, Bayfield County — 25 feet

The clearest monitored lake in northwest Wisconsin, 1,250 acres in the Chequamegon National Forest between Cable and Drummond. Readings since 1992 average almost 25 feet. Deep, cold, rock and sand bottom, almost no development on the national-forest shoreline. Two Lakes campground sits on it. It's an hour north of Hayward and worth the drive.

Photo: Stay Northern

Round Lake, Sawyer County — 22 feet

3,300 acres east of Hayward, and the clearest big lake in the Hayward area. Volunteers have measured it since 1995 and it has never classified as anything but oligotrophic. Sand flats you can wade a hundred yards out, then a drop to over 70 feet. Our Gratitude Up North cabin is on this lake.

Grindstone Lake, Sawyer County — 21 feet

Round Lake's neighbor to the west, 3,200 acres and 60 feet deep. Grindstone and Lac Courte Oreilles share a channel and a reputation for huge whitefish, cisco and smallmouth. A DNR-designated Outstanding Resource Water.

Sand Lake, Burnett County — 20 feet

900 acres and the surprise of the list: a lake most visitors drive past on the way to Webster that has posted 20-foot averages for forty years. Sand bottom, as the name says. Outstanding Resource Water.

Lac Courte Oreilles, Sawyer County — 16 feet

5,100 acres, the largest lake on this list and still clear, with readings going back to 1975. The deep basins hold trout and cisco; the bays hold musky. If you want big water that's also clean, this is it.

Deer Lake, Polk County — 15 feet

The clearest lake in Polk County and the only one in the St. Croix Falls area on this list. A 2019 reading of 30 feet made the statewide top ten; the forty-year average is a more honest 14–15 feet, which is still exceptional this far south.

Island Lake, Washburn County — 14 feet

Small, deep and quiet, monitored since 2001 with a 14-foot average. Little public pressure. The kind of lake you find because someone local told you.

South Twin Lake, Washburn County — 14 feet

Thirty years of readings averaging 14 feet. Oligotrophic, undeveloped stretches of shore, good for a paddle when the bigger lakes are blowing.

Lake Nancy, Washburn County — 14 feet

Near Minong, 25 years of data averaging 13.6 feet. The southeast basin is the deep, clear end.

Shell Lake, Washburn County — 13 feet

2,500 acres with no inlet and no outlet: it's fed by springs and rain, which is why it stays this clear at this size. Volunteers have measured it since 1976; the summer average is 13.2 feet and we see the bottom at 13 feet and more on calm days from our own dock. Sand bottom nearly everywhere, a public beach in town, five landings. Our Little Minnow Lake House is here.

Whitefish Lake, Sawyer County — 13 feet

800 acres south of Hayward near Stone Lake, 490 readings since 1986 averaging over 13 feet. Deep, cold, and as the name suggests, home to whitefish and cisco. Outstanding Resource Water.

Matthews Lake, Washburn County — 13 feet

Near Minong, 12.7-foot average since 1997. Small and lightly used; a good swimming lake.

Also Worth Knowing: Outstanding Resource Waters

Separate from clarity readings, the DNR designates a short list of lakes as Outstanding Resource Waters for exceptional water quality and minimal pollution. In our area that list includes Shell Lake, Big McKenzie and Middle McKenzie, Big Sand Lake and Sand Lake in Burnett County, Bass Lake near Webster, Long Lake and Bear Lake in Washburn County, Red Cedar Lake, Round Lake, Grindstone, Lac Courte Oreilles, Whitefish, Sand and Spider Lakes in Sawyer County, Teal Lake, Lake Chippewa, Nelson Lake, Trego Lake and Pipe Lake in Polk County.

Several of those (Big McKenzie at 11 feet, Big Sand at 12, Spider at 11) are a notch below the ranking above but still clear, cold and very good swimming. If a cabin you're looking at sits on one of these lakes, the water will not disappoint.

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Clear water, read before you jump

Clear lakes are clear because they're low in nutrients, and that usually means deep and cold. Expect the bottom to drop away fast past the sand shelf, and expect water in the 60s even in July on the deep ones. Swimmer's itch happens on clear lakes too; towel off hard when you get out. Bring a mask: off our own docks on Shell and Round you'll see fish, rock bars and the old sunken logs that make these lakes worth the trip, and the DNR's clarity numbers put Grindstone right there with them.

Clear Lakes FAQ

What is the clearest lake in northern Wisconsin?↓

Among lakes with long-term DNR monitoring in the northwest, Lake Owen in Bayfield County leads at about 25 feet of average summer visibility, followed by Round Lake and Grindstone Lake near Hayward at 21–22 feet. Statewide, a few lakes in Vilas, Oneida and Forest counties post similar numbers. Readings vary year to year with rain and algae, so treat any single-day figure with caution.

How is lake clarity measured?↓

With a Secchi disk, an eight-inch black-and-white disk lowered on a marked line until it disappears. The depth where it vanishes is the Secchi depth. Wisconsin's Citizen Lake Monitoring Network has volunteers doing this on hundreds of lakes every summer, and the DNR publishes the results. The numbers in this guide are long-term July–August averages from that program.

Why are some lakes clear and others not?↓

Low nutrients. Lakes fed by springs and groundwater, with sandy or rocky basins, forested shorelines and little farm or lawn runoff, grow very little algae, and algae is what turns water green and cuts visibility. Shell Lake is a good example: no river flows in or out, so nothing carries nutrients into it.

Is a clear lake good for fishing?↓

Good, but different. Fish can see you as well as you can see them, so clear lakes fish best at dawn, dusk and in deeper water, with lighter line. The upside is the species: the clear, cold lakes on this list hold whitefish, cisco, lake trout and big smallmouth that the fertile lakes don't.