Cook County · Minnesota

Alton Lake

Soundings in feet · 969 acres · deepest 72 ft

Where it is

17 miles northwest of Lutsen

Cook County, Minnesota · 47.8694° N, 90.9075° W

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The Minnesota DNR lists no public access site on Alton Lake; much of the shore may be private.

Today on the lake

Updated 19 Oct 2026, 5:56 pm EDT.

WEATHERThis Afternoon: sunny, 60°F, wind SE 5 mph. Tonight: mostly clear, 35°F, wind SE 0 to 5 mph.

WARNINGSNo weather or fire warnings in effect.

FIRENo wildfires or prescribed burns reported within 25 miles.

BURNINGCampfires and debris burning: check today's fire danger and burning restrictions with Minnesota DNR.

ALGAECAUTION Satellite detected cyanobacteria across about 10% of the lake on 11 Oct 2026, the latest clear-sky image.

National Weather Service; National Interagency Fire Center; U.S. EPA CyAN satellite; Minnesota DNR. Weather, warnings, fires and satellite refresh when you open the page (checked at most hourly).

Depth map

9 contours, 5 to 70 ft

051015203040506070feet

Minnesota DNR lake survey, fetched 15 Oct 2026. Not for navigation.

Fish survey

Minnesota DNR’s latest standard fish survey of Alton Lake was in September 2018: 12 gill nets caught 8 species. The DNR also ran a targeted survey in August 2025; this section uses the latest standard survey.

Fish per gill net, 12 sets. Line: Alton Lake. Bracket: normal for similar lakes.

Smallmouth bass3.8above normal

Walleye3.6normal

Rock bass2.0normal

Northern pike0.6normal

Yellow perch0.4normal

Walleye per gill net, standard surveys: 1990 1.0 · 1996 2.1 · 2003 6.0 · 2008 4.5 · 2018 3.6

Sizes in the nets

Walleye: 42 measured, 9 to 24 in, half 15 in or longer; average 1.3 lb, normal (normal 1.1–3.3 lb).

Northern pike: 8 measured, 11 to 23 in, half 21 in or longer; average 2.3 lb, below normal (normal 2.7–5.3 lb).

Smallmouth bass: 70 measured, 2 to 18 in, half 10 in or longer; average 1.7 lb, above normal (normal 0.7–1.4 lb).

Yellow perch: 9 measured, 2 to 7 in, half 5 in or longer; average 0.1 lb, normal (normal 0.1–0.2 lb).

Also caught: tullibee (cisco), white sucker.

Source: Minnesota DNR Fisheries lake survey, 10 Sep 2018, via LakeFinder, fetched 15 Oct 2026. Normal range: DNR’s range for lakes of the same class (43 classes, grouped by water chemistry and shape). Each line has its own scale. How we measure

Water quality

Measured water clarity averages about 14 ft: the Secchi depth across 6 readings, 2008–2025.

Clarity 14.2 ft of 72 ft

Minnesota Pollution Control Agency and volunteer Secchi readings, via Minnesota DNR LakeFinder, fetched 15 Oct 2026.

Nearby lakes with measured depth

Wonder Lake10 ft deep · 2.2 mi · Cook County

Crescent Lake28 ft deep · 7.5 mi · Cook County

Tait Lake15 ft deep · 10.4 mi · Cook County

Toohey Lake11 ft deep · 10.5 mi · Cook County

Brule Lake78 ft deep · 11.6 mi · Cook County

Perent Lake38 ft deep · 11.7 mi · Lake County

Minnesota DNR lake survey; straight-line miles.

Common questions

How deep is Alton Lake?

Alton Lake is 72 feet at its deepest point, measured by Minnesota DNR survey. It covers 969 acres.

What fish are in Alton Lake?

Minnesota DNR’s September 2018 standard survey caught 8 species, most often smallmouth bass, walleye, rock bass and northern pike.

How much of Alton Lake is deeper than 10 feet?

About 79% of the lake's area is deeper than 10 feet, measured from Minnesota DNR depth contours.