Keweenaw County · Michigan

Lake Gratiot

Soundings in feet · 1,452 acres · deepest 70 ft

Where it is

13 miles east of Copper City

Keweenaw County, Michigan · 47.3541° N, 88.1275° W

Directions to Gratiot Lake Apple Maps

Directions open in Google or Apple Maps, to the Michigan DNR public access site.

Today on the lake

Updated 10 Oct 2026, 12:27 am EDT. Get alerts for Lake Gratiot

WEATHEROvernight: partly cloudy, 47°F, wind SE 10 mph. Saturday: mostly sunny, 78°F, wind S 10 to 15 mph.

WARNINGSSpecial Weather Statement.

FIRENo wildfires or prescribed burns reported within 25 miles.

BURNINGCampfires and debris burning: check today's status with Michigan DNR.

ALGAECAUTION Satellite detected cyanobacteria across about 21% of the lake on 5 Oct 2026, the latest clear-sky image.

LAUNCHESGratiot Lake: listed open. Michigan DNR record updated 28 Aug 2026.

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

Depth map

8 contours, 5 to 70 ft

0510203040506070feet

Michigan DNR survey, fetched 7 Oct 2026. Not for navigation.

Size and depth

1,452 acres · deepest 70 ft (measured) · shoreline about 6.7 mi · clarity about 13 ft

Lake Gratiot is the 2nd largest of the 65 named lakes of 10 acres or more in Keweenaw County. By Michigan DNR survey it is the deepest of the 7 with a measured depth. Its water is clearer than 49 of the other 54 lakes in the county with satellite clarity readings. Its shoreline measures about 6.7 miles along the state outline. About 65% of its area is deeper than 30 ft.

Ranks against Keweenaw County lakes in Michigan hydrography, Michigan DNR lake surveys and Michigan EGLE satellite clarity; shoreline measured from the state outline. How we measure

Getting on the water

1 public access site on Lake Gratiot.

Gratiot Lake · Fort Wilkins State Historic Park · Open

1 ramp lane · 5 trailer spaces · vault toilet · Recreation Passport required

Local boating rules, Keweenaw County

Michigan DNR boating access, fetched 7 Oct 2026.

Fishing

Michigan DNR has stocked Lake Gratiot 26 times since 1979. The most recent stocking was 8,850 brook trout on 15 May 2008. Species stocked: brook trout, rainbow trout, smallmouth bass, tiger muskellunge, walleye.

26 stockings, 1979 to 2008, log scale

Latest: 15 May 2008: 8,850 brook trout.

15 May 2008STOCKED8,850 brook trout

9 Nov 2006STOCKED9,065 brook trout

25 May 2006STOCKED9,695 brook trout

23 Jun 2004STOCKED25,125 walleye

22 Jun 2004STOCKED11,023 walleye

3 Jul 2002STOCKED33,358 walleye

Source: Michigan DNR Fisheries, fetched 7 Oct 2026. How we measure

Where the deep water is

Show water deeper than

Measured from Michigan DNR contours. How we measure

Historically recorded species, from records through 1932: bluntnose minnow, brook stickleback, iowa darter, johnny darter, mottled sculpin, ninespine stickleback, northern logperch, northern pike, rock bass, smallmouth bass, trout-perch, white sucker, yellow perch. Historic records, not a current survey.

Michigan Fish Atlas.

Water quality

Average water clarity is about 13 ft (Secchi depth 4.1 m, satellite readings 2018–23).

Clarity 13.3 ft of 70 ft

Michigan EGLE satellite clarity, fetched 7 Oct 2026.

Email me about Lake GratiotWhen it is stockedMichigan DNR has stocked Lake Gratiot 26 times since 1979, most recently 8,850 brook trout on 15 May 2008. None in the last five years.When algae is reported or testedMichigan DHHS lists 3 bloom reports and 2 water samples here. None in 2026.When satellite sees a bloom startEPA satellite, checked daily, June to October. We email when a bloom first shows on two clear days, not every day it stays. In 2026 that happened on 5 Sep.Any lake in Keweenaw CountyStockings and algae records on every lake in the county. In 2026 so far: 5 emails.

In 2026 so far, these alerts would have sent you 1 email about Lake Gratiot: 5 Sep.

Email address

At most one email a week per lake. We email you a link to confirm before any alert is sent; every email has a one-click unsubscribe.

The area around Lake Gratiot

26 other lakes of 10+ acres within about 14 miles of Lake Gratiot, 1 with a page here (darker blue); 1 public launch in magenta. Sources: Michigan DNR, US Census Bureau.

Nearby lakes with measured depth

Deer Lake15 ft deep · 4.1 mi · Keweenaw County

Lac La Belle38 ft deep · 6.5 mi · Keweenaw County

Lake Bailey9 ft deep · 7.1 mi · Keweenaw County

Thayer Lake5 ft deep · 7.6 mi · Keweenaw County

Lake Glazon7 ft deep · 10.3 mi · Keweenaw County

Lake Manganese25 ft deep · 13.4 mi · Keweenaw County

Michigan DNR survey; straight-line miles.

Common questions

How deep is Lake Gratiot?

Lake Gratiot is 70 feet at its deepest point, measured by Michigan DNR survey. It covers 1,452 acres.

Is there a public boat launch on Lake Gratiot?

Yes. 1 public access site is listed: Gratiot Lake.

Is Lake Gratiot stocked with fish?

Yes. Michigan DNR has stocked it 26 times since 1979, most recently 8,850 brook trout on 15 May 2008.

How much of Lake Gratiot is deeper than 10 feet?

About 81% of the lake's area is deeper than 10 feet, measured from Michigan DNR depth contours.