Big Saint Germain Lake
Vilas County, Wisconsin · WBIC 1591100
Size
1,617 acres
Max depth
42 ft
DNR lake type
Complex, Two Story
Water clarity
10.5 ft
Clear, measured Oct 2024
A deep lake type that can hold a cold layer below the warm surface in summer. This describes the lake type in general, not this lake in particular.
Outline
Numbered dots are boat landings; tap one for directions. The list below has the same numbers. Drawn from the DNR's 24K hydrography (surveyed 1982), so the shape is approximate and a landing can sit a little off the shore. Open the DNR lake map.
Water clarity
10.5 ft Secchi depthClear
Last measured Oct 21, 2024. 316 readings on record, 1989 to 2024.
Typical summer clarity (June to September): 9.6 ft, moderate, from 126 readings (2012 to 2024).
Measured at the monitoring station named “Big St Germain Lake - Deep Hole”.
Secchi depth is how far down a white disk stays visible. A bigger number means clearer water. Clear means a Secchi depth of 10 feet or more, moderate 5 to 10 feet, low under 5 feet.
Wisconsin DNR water monitoring (volunteer and staff), via the Water Quality Portal; station Big St Germain Lake - Deep Hole. Checked Oct 23, 2026.
Water temperature
Last measured Aug 24, 2024, too long ago to show as the current temperature.
A typical year Modeled estimate
- Ice goes outabout Apr 24 (Apr 16 to May 2)
- Surface reaches 48°Fabout May 5 (Apr 30 to May 13)
- Surface reaches 64°Fabout Jun 7 (May 31 to Jun 10)
- June surface68°F, usually 66 to 69°F
- July surface74°F, usually 73 to 76°F
- August surface73°F, usually 71 to 74°F
Forms a warm top layer around Jul 4, lasting about 32 days.
A computer model of this lake's typical weather and water, built from 13 years, 2005 to 2019. Ranges show the middle half of years. The model was not calibrated against measured temperatures for this lake. It is an estimate, not a measurement.
Measured: Wisconsin DNR via the Water Quality Portal (checked Oct 23, 2026). Modeled: U.S. Geological Survey lake temperature data release (doi:10.5066/P9CA6XP8).
Today at the lake
Forecast: National Weather Service (no endorsement implied). Sunrise, sunset and moon phase are calculated. The moon phase can be a day off.
Stocking history
- Muskellungelast stocked 2025 (large fingerling); stocked in 8 years since 2010
- Walleyelast stocked 2024 (large fingerling and small fingerling); stocked in 15 years since 2010
Stocking shows what was added to the lake, not what is in it now.
Wisconsin DNR annual fish stocking summary. Checked Oct 23, 2026.
Fish recorded near this lake
- Black Crappie Pomoxis nigromaculatus2005; 2 records
- Bluegill Lepomis macrochirus1925 to 2005; 4 records
- Bluntnose Minnow Pimephales notatus1925 to 2005; 3 records
- Common Shiner Luxilus cornutus2005; 2 records
- Iowa Darter Etheostoma exile1925 to 2005; 2 records
- Johnny Darter Etheostoma nigrum1925 to 2005; 2 records
- Largemouth Bass Micropterus salmoides1925 to 2005; 5 records
- Mimic Shiner Notropis volucellus2005; 2 records
- Mottled Sculpin Cottus bairdii1925 to 2005; 3 records
- Muskellunge Esox masquinongy1994 to 2006; 4 records
- Northern Pike Esox lucius2004 to 2005; 3 records
- Pumpkinseed Lepomis gibbosus1925 to 2005; 2 records
- Rock Bass Ambloplites rupestris1925 to 2005; 4 records
- Rosyface Shiner Notropis rubellus1925; 1 record
- Smallmouth Bass Micropterus dolomieu2004 to 2005; 3 records
- Walleye Sander vitreus1994 to 2006; 6 records
- White Sucker Catostomus commersonii1925 to 2005; 3 records
- Yellow Bullhead Ameiurus natalis2005; 1 record
- Yellow Perch Perca flavescens1925 to 2005; 4 records
Recorded in open fish survey and museum records (GBIF). A record shows a fish was found near this lake in that year, not that it is there now, and says nothing about how many. Most coordinates are rounded to about 1 km, so a record is attached only when one lake is the clear match.
Open fish survey and museum records from GBIF; datasets are listed on the sources page. Checked Oct 23, 2026.
Boat landings
- 1Big Saint Germain Lake Boat RampBoat ramp · Concrete Panels surface · Accessible features · State(dnr)
Directions
Wisconsin DNR public boat access sites. Checked Oct 23, 2026.
More lakes in Vilas County
- Fawn Lake1.0 miles away
- Lake Content1.1 miles away
- Kasomo Lake1.4 miles away
- Little Bass Lake2.4 miles away
- Little Cloud Lake2.4 miles away
- Lost Lake2.8 miles away
Where this comes from
- Size, depth and lake typeWisconsin DNR lake classifications, checked Oct 23, 2026
- OutlineWisconsin DNR 24K hydrography, checked Oct 23, 2026
- Stocking historyWisconsin DNR annual fish stocking summary, checked Oct 23, 2026
- Regulations linkWisconsin DNR fishing regulations (linked, not restated), checked Oct 23, 2026
- Boat landingsWisconsin DNR public boat access sites, checked Oct 23, 2026
- Water clarityWisconsin DNR water monitoring, via the Water Quality Portal, checked Oct 23, 2026
- Typical-year temperatureU.S. Geological Survey lake temperature model (modeled estimate), checked Oct 23, 2026
- Fish recordedOpen fish survey and museum records, via GBIF, checked Oct 23, 2026
- VHS statusWisconsin DNR VHS status by watershed, checked Oct 24, 2026
- Depth map linkWisconsin DNR lake maps list, checked Oct 24, 2026
See data sources for what each source covers, and about for how the numbers are matched to lakes.
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