Thornapple Lake

Barry County, Michigan · MI DNR bathymetric survey

30ft Max
depth

402 acres 5 contours Public access

Paddling Index55Mixed

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Depth scale

0510152030

Michigan state-record water

The state-record Muskellunge (Northern) — 49.75 lb — was caught here in 2000. 51″ · Baitcasting · on Crankbait

The lake

Survey readout

Thornapple Lake is mapped to a depth of 30 ft on the Michigan DNR survey and covers about 402 acres in Barry County, Michigan.

Measured from the Michigan DNR inland-lake contour survey (depths read from the survey's isobath field; this lake's summary-depth column is blank in the source).

Deepest mapped contour: 30 ft
Mean depth: 13.1 ft · estimated
Surface area: 402 acres
Estimated volume: 5,263 acre-ft · 1,715M gal
Shoreline: 5.72 mi · irregular
Aquatic vegetation: 8% of surface · NDVI estimate
Public access: Boat Launch

Additional depth details5 contours

Contour depths: 0–30 ft
Recorded point soundings: 30 ft

31% of the surface sits over water shallower than 10 ft; 23.5% is deeper than 20 ft; the survey shows 2 distinct basins. Depth, area and volume are estimated from the interpolated survey surface — historical reference, not measurement.

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Location

Barry County, Michigan · 15 nearest of 47 lakes · tap a dot for that lake

Chart data

Provenance

Sources: MI DNR inland lake contours, USGS 3DEP, USDA NAIP (public domain), OpenStreetMap (ODbL), MI DNR Boat Launches.

⚠ Not for navigation

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Map details & sources5 sources

All layers registered to one bounding box; positions in WGS 84.

Survey-derived depth contours drape over USGS 3DEP elevation, with a USDA NAIP aerial basemap and OpenStreetMap shoreline. Colour shows surveyed depth; dark lines are the survey's own isobaths.

Coordinates: 42.62234, -85.18929
MI DNR lake ID: L20972
Vertical exaggeration: 2.66×
Basemap: USDA NAIP · public domain
Model size: 2.5 MB

Paddling

Paddling Index methodology v1.0 · calculated 2026-08-21

55 / 100MixedData confidence: High

Thornapple Lake has a partly natural setting, moderate open-water exposure, nearby higher-volume roads. No special watercraft restriction is identified in the current source.

Why this score?5 components

Included in the index

Component	Rating	Points of weight	Measurement
Natural setting	Good	16.6 of 30	62% natural land cover within 150 m of shore (9% forest, 52% wetland; 26% developed)
Geometric wind exposure	Good	12.4 of 25	mean fetch 1,371 m · 4% of sampled water within 500 m of shelter · moderate open-water fetch
Watercraft controls	None identified	7.5 of 15	No special watercraft restriction identified in the current DNR source. Motors permitted, subject to general law.
Public access	Good	12.8 of 15	2 sites with DNR boating-facility records · 3 ramp lanes · 32 trailer spaces
Road isolation	Mixed	6.2 of 15	nearby higher-volume roads · 23 MDOT-classified segments within 1.2 km, peak 4,718 vehicles/day

Additional paddling considerations

These describe the lake but are not part of the v1 Paddling Index and do not change the number above.

Wake sensitivity: Low — wide enough that wakes disperse over most of the lake
Aquatic vegetation: Low — approximately 8% mapped coverage · NAIP aerial imagery (NDVI)
Observed motorized activity: Unknown — No lake-level measurement of boat traffic is available. Legal permission to operate motors is not evidence of use.
Wildlife habitat potential: High — 9% forest and 52% wetland cover within 150 m of shore

Compare Michigan lakes by Paddling Index →

How this index is calculated. The Paddling Index is a relative composite derived from lake geometry and public environmental, access, roadway and watercraft-control data. It is not a user review, a safety rating, or a prediction of an individual outing. Differences of a few points should not be treated as meaningful — an 84 and an 82 are broadly comparable. Components and weights: natural setting 30%, geometric wind exposure 25%, watercraft controls 15%, public access 15%, road isolation 15%; observed motorboat activity is weighted 0% because no defensible lake-level measurement exists. Where a component has no data the remaining weights are renormalized and the confidence rating is lowered; below Medium confidence no number is shown. Sources: MI DNR Boating Access Sites (2026-08), MI DNR Watercraft Control Areas (2026-08), USGS/MRLC NLCD Land Cover (2021), MDOT Annual Average Daily Traffic (2025) and MI DNR bathymetric survey outline (0 ft isobath). Conditions change quickly — check current weather and local conditions before going out.

Fish you might catch

from angler catches, DNR surveys & active stocking

16 species with recent evidence in this lake — sized relative to each other. Illustrations are AI-generated representative adults in everyday colours, not photographs (provenance).

Muskellunge

Longnose Gar

Northern Pike

Common Carp

Bowfin

Walleye

Redhorse

Redhorse Sucker

Largemouth Bass

White Sucker

Shorthead Redhorse

Bullhead Species

Crappie

Rock Bass

Brook Silverside

Central Mudminnow

Fishing rules for this lake Beta

Size and daily limits for the 16 species found here — 13 open to harvest, 3 with a special rule or closed season.

These are hook-and-line size, daily limit and season rules. Gear, spearing and bow fishing, spawning closures and rod limits are set by other Fisheries Orders and are not shown here.

MuskellungeSpecial rulesNamed in a fisheries order for this lake — see the rule text below

RedhorseSpecial rulesMost redhorse suckers have no size limit, no possession limit and are open all year. River Redhorse is state-protected and may not be taken.

Beta. This panel is newly published. Every value is parsed from the Michigan DNR fisheries orders and hand-checked against the printed digest, but the coverage and wording are still under review. If anything here disagrees with the Michigan DNR's Fisheries Orders or its printed digest, the DNR is right — the signed Fisheries Order is the legal text; the digest summarises it.

BowfinOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

Brook SilversideOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

Bullhead SpeciesOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

Central MudminnowOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

Common CarpOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

CrappieOpen to harvestMinimum size: no size limit · Daily limit: 25 (FO-215 · statewide inland) The 25 is in any combination of the sunfishes — Bluegill, Pumpkinseed, Black and White Crappie, Rock Bass, Green, Longear and Redear Sunfish, Warmouth and hybrids — not 25 of each (FO-215.23A).

Largemouth BassOpen to harvestMinimum size: 14" · Daily limit: 5 (FO-215 · statewide inland) The 5 is in any combination of Largemouth and Smallmouth Bass, not 5 of each (FO-215.23A).

Longnose GarOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

MuskellungeSpecial rulesNamed in a fisheries order for this lake — see the rule text below

Northern PikeOpen to harvestMinimum size: 24" · Daily limit: 2 (FO-215 · statewide inland)

RedhorseSpecial rulesMost redhorse suckers have no size limit, no possession limit and are open all year. River Redhorse is state-protected and may not be taken.

Redhorse SuckerSpecial rulesMost redhorse suckers have no size limit, no possession limit and are open all year. River Redhorse is state-protected and may not be taken.

Rock BassOpen to harvestMinimum size: no size limit · Daily limit: 25 (FO-215 · statewide inland) The 25 is in any combination of the sunfishes — Bluegill, Pumpkinseed, Black and White Crappie, Rock Bass, Green, Longear and Redear Sunfish, Warmouth and hybrids — not 25 of each (FO-215.23A).

Shorthead RedhorseOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

WalleyeOpen to harvestMinimum size: 15" · Daily limit: 5 (FO-215 · statewide inland)

White SuckerOpen to harvestMinimum size: no size limit · Daily limit: no possession limit (2026 DNR digest · all other species)

Official rule text for this lake

“the minimum size limit for Muskellunge is 50-inches.” — FO-206

From FO-206.26 (eff. 2026-04-01) / FO-215.23A (eff. 2023-09-15) / FO-254.25 (eff. 2025-10-10), checked against the 2026 Michigan Fishing Regulations digest · verified 2026-08-24. Regulations can change — Michigan DNR rules are the controlling source; verify current regulations before fishing. Official regulations

Compiled from registered Master Angler catches, Michigan DNR fishery surveys and Michigan DNR stockings within the last 10 years. Silhouettes are stylized and scaled to typical adult sizes relative to one another. Presence is not a promise — fishing isn’t a sure thing.

Notable catches

Master Angler program · 1996–2025

Trophy-size fish anglers caught here and registered with the DNR — what people have actually caught, distinct from what a survey netted or the state stocked below.

58Catches recorded

12Species

Muskellunge Northern1 recorded · to 51″

Muskellunge31 recorded · to 52.5″

Bowfin10 recorded · to 34″

Longnose Gar4 recorded · to 43″

Catch details by species12 species

Muskellunge31 recorded · to 52.5″ · latest 2025

Bowfin10 recorded · to 34″ · latest 2025

Longnose Gar4 recorded · to 43″ · latest 2025

Northern Pike4 recorded · to 39″ · latest 2025

Walleye2 recorded · to 29.5″ · latest 2017

Common Carp1 recorded · to 41″ · latest 2016

Crappie1 recorded · to 14.2″ · latest 2025

Largemouth Bass1 recorded · to 21.1″ · latest 2025

Muskellunge Northern1 recorded · to 51″ · latest 2000

Redhorse Sucker1 recorded · to 25″ · latest 1996

Rock Bass1 recorded · to 12.1″ · latest 2002

White Sucker1 recorded · to 21.5″ · latest 2024

Biggest on record

Muskellunge52.5″ · 2000 · spincasting

Muskellunge52″ · 2003 · spincasting

Muskellunge51″ · 2001 · spincasting

Muskellunge51″ · 2000 · spincasting

Muskellunge Northern51″ · 2000 · baitcasting · crankbait

Bait: artificial lure (15) · minnow (3) · worm (2)
Method: spincasting (38) · trolling (9) · still fishing (7) · spearfishing (1)

Master Angler entries are fish that met the program’s minimum size and were registered by the angler — they show what this lake has produced, not what a day here will produce. A catch on record is history, not a species listing: “Fish you might catch” lists only species with current evidence. Source: Michigan DNR Master Angler data.

Fishery

DNR SFR 2000-14

156Fish sampled

8Species

Gamefish Bowfin 11

All survey species8 species

Gamefish

Bowfin11 caught · to 30″

Forage & nongame

Redhorse72 caught · to 22″

Longnose Gar36 caught · to 39″

White Sucker20 caught · to 17″

Bullhead Species7 caught · to 14″

Shorthead Redhorse6 caught · to 24″

Brook Silverside2 caught · to 3″

Central Mudminnow2 caught · to 4″

Stocking: Fish stocking occurred there as early as 1934 according to Michigan Fish Commission reports, but Thornapple Lake may have been stocked in the late 1800s along with many other Michigan lakes.

Length is the largest fish netted in the survey, not an angler record. Source: Michigan DNR Status of the Fishery Resource report (counts summed across survey years).

DNR stocking

state stocking record · 1979–2025

Fish the Michigan DNR has planted in this lake — what was added, distinct from what a survey netted above.

Muskellunge44,110 stocked · 1979–2025 · 56 plantings

Walleye2,460,252 stocked · 1981–2019 · 31 plantings

Northern pike21 stocked · 1991–2001 · 2 plantings

Largemouth bass125 stocked · 1991

Source: Michigan DNR Fish Stocking Database.

Non-native species records

1 record

Plants & algae

Eurasian Watermilfoil

What does non-native mean?

USGS records identify non-native species that have been documented for this lake or its shoreline. Non-native does not necessarily mean invasive, and historical records do not confirm current presence.

Source: Midwest Glacial Lakes Partnership Conservation Planner; underlying nonindigenous species records from the USGS Nonindigenous Aquatic Species database.

Public fishing access

MI DNR family-friendly fishing

ShoreBoat

County-managed · Entry fee · Modern restrooms · Paved parking

Amenities: Boat launch, camping

“Maximum depth: 31 feet, water clarity: turbid, irregular bottom on east end, good weedlines along the steeper banks on lower end.”

Source: Michigan DNR Family Friendly Fishing.

At the lake

community-mapped amenities · straight-line distance

⛻ Campground≈0.6 mi

🚿 Restrooms / vault toileton the lake · 4 mapped

🏖 Beach / swim areaon the lake

🎢 Playgroundon the lake · 2 mapped

From OpenStreetMap community mapping — shown only where something is mapped; an amenity missing here may still exist. Distances are straight-line. Verify before you rely on it. © OpenStreetMap contributors (ODbL).

Bait & tackle nearby

licensed retail bait dealers · straight-line distance

AL & Pete's Sport Shop≈5.3 mi111 S Jefferson St, Hastings · Google · Apple

Bob's Guns & Tackle Shop≈7.5 mi2208 W Hwy M-43, Hastings · Google · Apple

Vern's Repair & Sport LLC≈11 mi11994 Grand Ledge Hwy, Lake Odessa · Google · Apple

Dealers licensed by the Michigan DNR to sell live bait; listing is not an endorsement. Distances are straight-line, not driving — and call ahead: hours and stock change. Source: Michigan DNR retail bait dealer data.

Quick answers

Thornapple Lake — common questions

How deep is Thornapple Lake?

The deepest contour on the Michigan DNR bathymetric survey of Thornapple Lake is 30 ft. That is the deepest depth the historical survey map records, which may differ from the deepest point of the lake itself.

How big is Thornapple Lake?

Thornapple Lake covers about 402 acres in Barry County, Michigan.

What is the average depth of Thornapple Lake?

The estimated mean depth of Thornapple Lake is 13.1 ft, calculated from the survey contours.

What fish are in Thornapple Lake?

Species with survey, catch or recent-stocking evidence include largemouth bass, muskellunge, northern pike, walleye, bowfin, crappie. The page lists all 16 species and the evidence behind each.

Is there public access to Thornapple Lake?

Yes. The Michigan DNR boat-launch data identifies 2 public access sites on Thornapple Lake, including Thornapple Lake.