Boy Lake

Cass County, Minnesota · MN DNR bathymetric survey

45ft Max
depth

3,466 acres 9 contours Public access

Paddling Index64Mixedwooded shoreline · away from major roads

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Depth scale

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The lake

Survey readout

Boy Lake is mapped to a depth of 45 ft on the Minnesota DNR survey and covers about 3,466 acres in Cass County, Minnesota. Depths come from the Minnesota DNR survey of 1940.

Measured from the Minnesota DNR lake bathymetric contour survey.

Deepest mapped contour: 45 ft
Survey year: 1940
Surface area: 3,466 acres
Shoreline: 25.47 mi · irregular
Aquatic vegetation: 1% of surface · NDVI estimate
Public access: Trailer Launch · Boy Lake Public Water Access Site · Minnesota DNR site

Additional depth details9 contours

Contour depths: 0–45 ft
Recorded point soundings: 45 ft

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Location

Cass County, Minnesota · 15 nearest of 123 lakes · tap a dot for that lake

Chart data

Provenance

Sources: MN DNR Lake Bathymetric Contours, USGS 3DEP, USDA NAIP (public domain), OpenStreetMap (ODbL).

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Map details & sources4 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. Color shows surveyed depth; dark lines are the survey's own isobaths.

Coordinates: 47.10743, -94.16314
MN DNR lake ID: 11014300
Vertical exaggeration: 2.15×
Basemap: USDA NAIP · public domain
Model size: 2.3 MB

Paddling

Paddling Index methodology v1.0 · calculated 2026-09-25

64 / 100MixedData confidence: High

Boy Lake has a heavily wooded and largely undeveloped setting, notable open-water exposure, limited nearby major-road exposure.

Why this score?5 components

Included in the index

Component	Rating	Points of weight	Measurement
Natural setting	Excellent	31.9 of 35	88% natural land cover within 150 m of shore (32% forest, 55% wetland; 8% developed)
Geometric wind exposure	Mixed	4.9 of 29	mean fetch 3,016 m · 0% of sampled water within 500 m of shelter · long fetch in some directions
Motor & speed rules	Not modeled	—	Minnesota’s lake-by-lake motor, speed and no-wake rules are mostly county and city ordinances, not map data, so they are not part of the Minnesota index. Check local signage and ordinances before going out.
Public access	Good	15.0 of 18	1 DNR public access site · boat ramp
Road isolation	Very Good	11.9 of 18	limited nearby major-road exposure · 6 MnDOT-classified segments within 1.2 km, peak 780 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 1% 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 — 32% forest and 55% wetland cover within 150 m of shore

Compare Minnesota lakes by Paddling Index →

How this index is calculated. The Paddling Index is a relative composite derived from lake geometry and public land-cover, access and traffic-count 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 for Minnesota lakes: natural setting 35%, geometric wind exposure 29%, public access 18%, road isolation 18%. Motor, speed and no-wake rules are not modeled for Minnesota, and traffic counts cover state, county and some city roads but not township roads. Where a component has no data the remaining weights are renormalized and the confidence rating is lowered; below Medium confidence no number is shown. Minnesota scores are relative to other Minnesota lakes and are not directly comparable with Paddling Index scores on our sister sites, which use different data sources, some with a watercraft-rules component. Sources: MN DNR lake bathymetry outline, USGS/MRLC NLCD Land Cover (2021), MN DNR Water Access Sites and Fishing Piers & Shore Fishing Sites (2026-09) and MnDOT Annual Average Daily Traffic (counts 2011–2023). Conditions change quickly — check current weather and local conditions before going out.

Fish you might catch

from DNR surveys

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

Greater Redhorse

White Sucker

Shorthead Redhorse

Hybrid Sunfish

About these fish → the Fish of Minnesota guide

Compiled from Minnesota DNR fishery surveys. Silhouettes are stylized and scaled to typical adult sizes relative to one another. Presence is not a promise — fishing isn’t a sure thing.

Fishery

surveyed 2025

1,107Fish sampled

18Species

Gamefish Northern Pike 209 · Walleye 60 · Largemouth Bass 26 · Bowfin 12

Panfish Bluegill 446 · Pumpkinseed 80 · Yellow Perch 60

All survey species18 species

Gamefish

Northern Pike209 caught · to 30″

Walleye60 caught · to 26″

Largemouth Bass26 caught · to 18″

Bowfin12 caught · to 25″

Smallmouth Bass7 caught · to 16″

Muskellunge1 caught · to 21″

Panfish

Bluegill446 caught · to 9″

Pumpkinseed80 caught · to 7″

Yellow Perch60 caught · to 9″

Black Crappie32 caught · to 14″

Rock Bass16 caught · to 9″

Hybrid Sunfish5 caught · to 8″

Bullhead & catfish

Yellow Bullhead91 caught · to 12″

Brown Bullhead45 caught · to 14″

Forage & nongame

Cisco7 caught · to 17″

White Sucker7 caught · to 18″

Greater Redhorse2 caught · to 27″

Shorthead Redhorse1 caught · to 16″

Length is the largest fish netted in the survey, not an angler record. Source: Minnesota DNR lake survey (LakeFinder).

Infested waters listing

1 confirmed

Mussels & snails

Zebra MusselConfirmed in this water in 2025 (listed 2025).

How to identify invasive species in Minnesota lakes →

What does the infested waters list mean?

The Minnesota DNR lists a lake, river, pond or wetland as infested when it contains an aquatic invasive species that could spread to other waters, or when it is connected to a water where one is present. Activities such as bait harvest and water use are managed differently on infested waters. Check the current list before moving water, bait or equipment.

Source: Minnesota Department of Natural Resources. List of Infested Waters, September 9, 2026. https://www.dnr.state.mn.us/invasives/ais/infested.html

Quick answers

Boy Lake — common questions

How deep is Boy Lake?

The deepest contour on the Minnesota DNR bathymetric survey of Boy Lake is 45 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 Boy Lake?

Boy Lake covers about 3,466 acres in Cass County, Minnesota.

What fish are in Boy Lake?

Species with survey, catch or recent-stocking evidence include largemouth bass, muskellunge, northern pike, smallmouth bass, walleye, black crappie. The page lists all 18 species and the evidence behind each.

Is there public access to Boy Lake?

Yes. The Minnesota DNR lists a public access site on Boy Lake: a boat ramp with a boat dock and restrooms. It is administered by the DNR Division of Parks and Trails. DNR directions: "9 mi NE of Longville on W shore."