Grassy Lake

Lenawee County, Michigan · MI DNR bathymetric survey

— Max
depth

61 acres 0 contours 32% weedy

Paddling Index76Goodwooded shoreline · away from major roads · sheltered geometry

Get directions

Depth scale

The lake

Survey readout

Grassy Lake covers about 61 acres in Lenawee County, Michigan. The Michigan DNR survey for this lake records a shoreline outline only, with no usable depth soundings, so a maximum depth cannot be stated.

Measured from the Michigan DNR inland-lake contour survey.

Bathymetric depth unavailable. The source survey does not contain sufficient usable depth information to calculate lake depth for Grassy Lake — the Michigan DNR record carries a shoreline outline without depth soundings. Surface area, location, access and fishery information below are unaffected.

Depth: Bathymetric depth unavailable
Surface area: 61 acres
Shoreline: 1.51 mi · irregular
Aquatic vegetation: 32% of surface · NDVI estimate
Public access: No public DNR launch identified

Additional depth details

Contour depths: shoreline only
Recorded point soundings: No point soundings recorded in source

Compare with another lake

Location

Lenawee County, Michigan · 15 nearest of 22 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

Spot an error? Send a correction

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: 42.04305, -84.24484
MI DNR lake ID: L10274
Vertical exaggeration: 3.0×
Basemap: USDA NAIP · public domain
Model size: 2.3 MB

Paddling

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

76 / 100GoodData confidence: High

Grassy Lake has a heavily wooded and largely undeveloped setting, generally sheltered geometry, limited nearby major-road exposure. 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	Excellent	24.7 of 30	79% natural land cover within 150 m of shore (12% forest, 66% wetland; 10% developed)
Geometric wind exposure	Very Good	20.9 of 25	mean fetch 633 m · 24% of sampled water within 500 m of shelter · generally short 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	1 site with DNR boating-facility records · 1 ramp lane · 4 trailer spaces
Road isolation	Very Good	10.5 of 15	limited nearby major-road exposure · 9 MDOT-classified segments within 1.2 km, peak 5,498 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: Moderate — narrow in places — wakes would carry across parts of the lake
Aquatic vegetation: Moderate — approximately 32% 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 — 12% forest and 66% 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.

Non-native species records

No non-native species recorded in the available dataset. This does not confirm that no non-native species are present.

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

At the lake

community-mapped amenities · straight-line distance

⛻ Campground≈0.7 mi · 6 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

Brooklyn Convenience LLC≈1.6 mi · (517) 467-246811700 M-50, Brooklyn · Google · Apple

Knutson's Recreational Sales≈3.9 miPO Box 457 - 164 Wamplers Lake, Brooklyn · Google · Apple

Manito Beach Marina≈5.4 mi9517 Devils Lake Hwy, Manitou Beach · 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

Grassy Lake — common questions

How deep is Grassy Lake?

The Michigan DNR survey for Grassy Lake contains no usable depth measurements, so a maximum depth cannot be stated.

How big is Grassy Lake?

Grassy Lake covers about 61 acres in Lenawee County, Michigan.

Is there public access to Grassy Lake?

No public launch for Grassy Lake appears in the Michigan DNR access data. That is not the same as the lake being private -- municipal and private ramps are not in that source.

More lakes in Lenawee County