Barry County · Michigan

Thornapple Lake

Soundings in feet · 415 acres · deepest 30 ft

Today on the lake

Updated 9 Oct 2026, 3:24 am EDT. Get alerts for Thornapple Lake

WEATHEROvernight: mostly clear, 43°F, wind SSW 3 mph. Friday: mostly sunny, 69°F, wind SSW 2 to 6 mph.

WARNINGSNo weather or fire warnings in effect.

FIRENo wildfires or prescribed burns reported within 25 miles.

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

ALGAENo cyanobacteria detected by satellite on 5 Oct 2026, the latest clear-sky image.

LAUNCHESCharlton Park and Thornapple Lake: listed open. Michigan DNR record updated 3 Apr 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

5 contours, 5 to 30 ft

0510152030feet

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

Size and depth

415 acres · deepest 30 ft (measured) · shoreline about 9.0 mi · clarity about 3 ft

Thornapple Lake is the 7th largest of the 125 named lakes of 10 acres or more in Barry County. By Michigan DNR survey it is the 27th deepest of the 44 with a measured depth. Its water is clearer than 2 of the other 94 lakes in the county with satellite clarity readings. Its shoreline measures about 9.0 miles along the state outline. About 49% of its area is deeper than 15 ft.

Ranks against Barry 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

2 public access sites on Thornapple Lake.

Charlton Park · Barry County · Open

2 ramp lanes · 16 trailer spaces · 1 car space · vault toilet · accessible restroom

Local boating rules, Barry County

Thornapple Lake · Yankee Springs State Recreation Area · Open

1 ramp lane · 16 trailer spaces · 2 car spaces · vault toilet · accessible restroom · Recreation Passport required

Local boating rules, Barry County

Michigan DNR boating access, fetched 7 Oct 2026.

Fishing

Michigan DNR has stocked Thornapple Lake 90 times since 1979. The most recent stocking was 870 muskellunge on 6 November 2025. Species stocked: largemouth bass, muskellunge, northern pike, walleye.

90 stockings, 1979 to 2025, log scale

Latest: 6 Nov 2025: 870 muskellunge.

6 Nov 2025STOCKED870 muskellunge

7 Jul 2025STOCKED161 muskellunge

11 Jun 2025STOCKED695 muskellunge

30 Oct 2024STOCKED823 muskellunge

11 Jun 2024STOCKED161 muskellunge

1 Nov 2023STOCKED817 muskellunge

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 1944: chestnut lamprey, longnose gar. Historic records, not a current survey.

Michigan Fish Atlas.

Water quality

Average water clarity is about 3 ft (Secchi depth 0.9 m, satellite readings 2018–23).

Clarity 2.8 ft of 30 ft

Michigan EGLE satellite clarity, fetched 7 Oct 2026.

CAUTION The highest toxin level measured here was microcystin at 119.2 ppb on 4 August 2025, 15 times the EPA swimming guideline of 8 ppb. 6 water samples are on record, the latest from 4 August 2025. Check current advisories before swimming.

Source: Michigan DHHS harmful algal bloom sampling; U.S. EPA 2019 recreational criteria. Fetched 7 Oct 2026.

Email me about Thornapple LakeWhen it is stockedMichigan DNR has stocked Thornapple Lake 90 times since 1979, most recently 870 muskellunge on 6 November 2025. None so far in 2026.When algae is reported or testedMichigan DHHS lists 2 bloom reports and 6 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 13 Jul.Any lake in Barry CountyStockings and algae records on every lake in the county. In 2026 so far: 3 emails.

In 2026 so far, these alerts would have sent you 1 email about Thornapple Lake: 13 Jul.

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.

Nearby lakes with measured depth

Middle Lake42 ft deep · 3.4 mi · Barry County

Middle Lake30 ft deep · 6.5 mi · Barry County

Leach Lake40 ft deep · 6.5 mi · Barry County

Myers Lake36 ft deep · 6.7 mi · Barry County

Carter Lake20 ft deep · 7.0 mi · Barry County

Tillotson Lake26 ft deep · 7.9 mi · Barry County

Michigan DNR survey; straight-line miles.

Common questions

How deep is Thornapple Lake?

Thornapple Lake is 30 feet at its deepest point, measured by Michigan DNR survey. It covers 415 acres.

Is there a public boat launch on Thornapple Lake?

Yes. 2 public access sites are listed: Charlton Park; Thornapple Lake.

Is Thornapple Lake stocked with fish?

Yes. Michigan DNR has stocked it 90 times since 1979, most recently 870 muskellunge on 6 November 2025.

How much of Thornapple Lake is deeper than 10 feet?

About 9% of the lake's area is deeper than 10 feet, measured from Michigan DNR depth contours.

Has Thornapple Lake had toxic algae?

The highest toxin level measured was microcystin at 119.2 ppb (4 August 2025). Check current advisories before swimming.