Long Lake
depth
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Depth scale
Survey readout
Long Lake is mapped to a depth of 41 ft on the Michigan DNR survey and covers about 208 acres in St. Joseph County, Michigan.
Measured from the Michigan DNR inland-lake contour survey.
- Deepest sounding
- 41 ft
- Mean depth
- 16.5 ft · estimated
- Surface area
- 208 acres
- Estimated volume
- 3,425 acre-ft · 1,116M gal
- Shoreline
- 3.63 mi · irregular
- Aquatic vegetation
- 5% of surface · NDVI estimate
- Public access
- Boat Launch
Additional depth details7 contours
- Contour depths
- 0–41 ft
- Recorded point soundings
- 41 ft, 34 ft
32.6% of the surface sits over water shallower than 10 ft; 42.1% 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 Depth, area and volume are estimated from the interpolated survey surface — historical reference, not measurement.
Compare with another lakeProvenance
Sources: MI DNR inland lake contours, USGS 3DEP, USDA NAIP (public domain), OpenStreetMap (ODbL), MI DNR Boat Launches.
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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
- 41.95726, -85.75108
- MI DNR lake ID
- L31281
- Vertical exaggeration
- 2.29×
- Basemap
- USDA NAIP · public domain
- Model size
- 2.3 MB
Watercraft rules
county-enforced local controls · MI DNROfficial rule details1 rule
Paddling
Paddling Index methodology v1.0 · calculated 2026-08-21Long Lake has a substantially developed setting, generally sheltered geometry, nearby higher-volume roads. Watercraft controls: Restricted hours.
Why this score?5 components
Included in the index
| Component | Rating | Points of weight | Measurement |
|---|---|---|---|
| Natural setting | Modest | 6.0 of 30 | 37% natural land cover within 150 m of shore (27% forest, 10% wetland; 38% developed) |
| Geometric wind exposure | Very Good | 15.4 of 25 | mean fetch 1,011 m · 0% of sampled water within 500 m of shelter · generally short fetch |
| Watercraft controls | Restricted hours | 9.3 of 15 | Restricted hours |
| Public access | Good | 12.8 of 15 | 1 site with DNR boating-facility records · 1 ramp lane · 5 trailer spaces |
| Road isolation | Mixed | 5.7 of 15 | nearby higher-volume roads · 38 MDOT-classified segments within 1.2 km, peak 2,068 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 5% 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
- Limited — 27% forest and 10% wetland cover within 150 m of shore
Compare Michigan lakes by Paddling Index →
Fish you might catch
from angler catches8 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
Smallmouth Bass
Bullhead
Crappie
Redear Sunfish
Yellow Perch
Bluegill
Rock BassFishing rules for this lake Beta
Size and daily limits for the 8 species found here — 8 open to harvest.
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.
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
Notable catches
Master Angler program · 1999–2023Trophy-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.
Catch details by species8 species
Biggest on record
Bait: artificial lure (2) · night crawler (1)
Method: trolling (3) · spincasting (3) · drift fishing (2)
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 distanceBait & tackle nearby
licensed retail bait dealers · straight-line distanceLong Lake — common questions
How deep is Long Lake?
The deepest contour on the Michigan DNR bathymetric survey of Long Lake is 41 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 Long Lake?
Long Lake covers about 208 acres in St. Joseph County, Michigan.
What is the average depth of Long Lake?
The estimated mean depth of Long Lake is 16.5 ft, calculated from the survey contours.
What fish are in Long Lake?
Species with survey, catch or recent-stocking evidence include muskellunge, smallmouth bass, bluegill, bullhead, crappie, redear sunfish. The page lists all 8 species and the evidence behind each.
Is there public access to Long Lake?
Yes. The Michigan DNR boat-launch data identifies 1 public access site on Long Lake, including Long Lake.
