Lake Gratiot
depth
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Depth scale
Survey readout
Lake Gratiot is mapped to a depth of 70 ft on the Michigan DNR survey and covers about 1,479 acres in Keweenaw County, Michigan.
Measured from the Michigan DNR inland-lake contour survey.
- Deepest mapped contour
- 70 ft
- Mean depth
- 27.5 ft · estimated
- Surface area
- 1,479 acres
- Estimated volume
- 40,630 acre-ft · 13,239M gal
- Shoreline
- 6.72 mi · lobed
- Aquatic vegetation
- 2% of surface · NDVI estimate
- Public access
- Boat Launch
Additional depth details8 contours
- Contour depths
- 0–70 ft
- Recorded point soundings
- 70 ft
20.6% of the surface sits over water shallower than 10 ft; 71.4% is deeper than 20 ft. Depth, area and volume are estimated from the interpolated survey surface — historical reference, not measurement.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
- 47.35836, -88.12462
- MI DNR lake ID
- L32891
- Vertical exaggeration
- 1.4×
- Basemap
- USDA NAIP · public domain
- Model size
- 2.4 MB
Paddling
Paddling Index methodology v1.0 · calculated 2026-08-21Lake Gratiot has a heavily wooded and largely undeveloped setting, notable open-water exposure, 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 | 24.9 of 30 | 84% natural land cover within 150 m of shore (57% forest, 25% wetland; 8% developed) |
| Geometric wind exposure | Mixed | 4.4 of 25 | mean fetch 2,942 m · 0% of sampled water within 500 m of shelter · long fetch in some directions |
| 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 · 8 trailer spaces |
| Road isolation | Very Good | 11.7 of 15 | limited nearby major-road exposure · 2 MDOT-classified segments within 1.2 km, peak 199 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 2% 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 — 57% forest and 25% wetland cover within 150 m of shore
Compare Michigan lakes by Paddling Index →
Fish you might catch
from angler catches & active stocking6 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
Northern Pike
Smallmouth Bass
Brook Trout
Yellow Perch
Rock BassHistorically stocked, no recent evidence: Walleye (last planted 2004), Rainbow Trout (last planted 1991), Tiger Muskellunge (last planted 1980) — not shown above.
Fishing rules for this lake Beta
Size and daily limits for the 6 species found here — 6 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.
Official rule text for this lake
“protected slot limit on Walleye from 18 – 23 inches; with no more than one (1) greater than 23-inches. This regulation will expire on April 1, 2038.” — 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
Notable catches
Master Angler program · 1998–2025Trophy-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.
Biggest on record
Bait: artificial lure (2) · crawler (1) · creek sucker (1)
Method: spincasting (4) · trolling (3) · still fishing (2)
DNR stocking
state stocking record · 1979–2008Fish the Michigan DNR has planted in this lake — what was added, distinct from what a survey netted above.
No stockings recorded since 2008 — shown as history.
Non-native species records
1 recordPlants & algae
- Purple Loosestrife
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.
At the lake
community-mapped amenities · straight-line distanceLake Gratiot — common questions
How deep is Lake Gratiot?
The deepest contour on the Michigan DNR bathymetric survey of Lake Gratiot is 70 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 Lake Gratiot?
Lake Gratiot covers about 1,479 acres in Keweenaw County, Michigan.
What is the average depth of Lake Gratiot?
The estimated mean depth of Lake Gratiot is 27.5 ft, calculated from the survey contours.
What fish are in Lake Gratiot?
Species with survey, catch or recent-stocking evidence include brook trout, muskellunge, northern pike, smallmouth bass, rock bass, yellow perch. The page shows the evidence behind each.
Is there public access to Lake Gratiot?
Yes. The Michigan DNR boat-launch data identifies 1 public access site on Lake Gratiot, including Gratiot Lake.
