About Grassy Lake
Grassy Lake is a scenic Columbia County lake worth knowing about, covering 250 acres. The lake has public boat landing access, making it easy to launch for a day on the water.
Type: lake
Lake Location
43.42420° N, 89.16970° W
WBIC 776400 · Wisconsin DNRLocal's Guide
Fishing
Species-specific tips above. Wisconsin fishing license required for ages 16+. See current season regulations below.
View fishing regulations ↓Swimming
Grassy Lake has limited visibility and a mixed bottom, making it generally good for swimming with gradual entry in most areas. The 250-acre lake offers a quieter, more intimate swimming experience.
Nearby Dining
Local dining recommendations for Grassy Lake are coming soon. Know a great spot near Grassy Lake? Share it at staynorthern.com/contact. Looking for restaurants near Columbia County lakes? Visit staynorthern.com/eats for our full northwoods dining guide.
Insider Tips
Grassy Lake is one of Columbia County's lesser-known gems — the kind of place locals return to year after year. Early mornings before 9am offer the calmest water and best fishing before boat traffic picks up. If you're visiting for the first time, check the DNR boat landing locations before you arrive — some are well-marked, others take a local to find. Know something about Grassy Lake that visitors should? Share a tip at staynorthern.com/contact — we add the best ones to this page.
Lake Conditions
Water Clarity
—
No data
Trophic Status
—
No data
Invasive Weeds
Not documented
Clean lake
Seasonal Notes
See below
Ice-out dates, peak fishing windows
Ice out arrives in late March to early April on southern Wisconsin lakes. Bass and panfish fishing is excellent from early May onward. Swimming season runs from early June through September. Fall color peaks in mid-October. Ice fishing is possible in most winters but season length varies — check conditions before heading out.
Condition data sourced from Wisconsin DNR surveys. Real-time weed and clarity reports coming soon.
Frequently Asked Questions
Is there a public boat launch on Grassy Lake?
Yes — Grassy Lake has a public boat landing providing watercraft access. Check for posted local ordinances at the landing before launching.
How big is Grassy Lake?
Grassy Lake has 250 acres in surface area.
Are there invasive species in Grassy Lake?
No invasive species are currently documented in Grassy Lake by the Wisconsin DNR. Always clean, drain, and dry your boat before leaving to help protect this lake.
Where is Grassy Lake located?
Grassy Lake is located in Columbia County, Wisconsin. GPS coordinates: 43.4242° N, 89.1697° W.
Are there vacation rentals on Grassy Lake?
Stay Northern is building the most complete rental directory for Columbia County lakes. Check our Grassy Lake vacation rentals listing — if none are available yet, check back soon or browse nearby Columbia County lake rentals.
Fishing Regulations
Current season regulations for Grassy Lake
| Species | Season | Min. Length | Daily Bag |
|---|---|---|---|
| Bullheads | Open All Year | No minimum length limit and the daily bag limit is unlimited. | — |
| Catfish | Open All Year | No minimum length limit and the daily bag limit is 10. | — |
| Cisco And Whitefish | Open All Year | No minimum length limit and the daily bag limit is 10. | — |
| Lake Sturgeon | Closed | No fishing allowed. | — |
| Largemouth Bass And Smallmouth Bass | May 2, 2026 to March 7, 2027 | The minimum length limit is 14" and the daily bag limit is 5. | — |
| Muskellunge And Hybrids | May 2, 2026 to December 31, 2026 on open water | The minimum length limit is 40" and the daily bag limit is 1. | — |
| Northern Pike | May 2, 2026 to March 7, 2027 | The minimum length limit is 26" and the daily bag limit is 2. | — |
| Paddlefish | Closed | No fishing allowed. | — |
| Panfish | Open All Year | No minimum length limit and the daily bag limit is 25. | — |
| Rock, Yellow, And White Bass | Open All Year | No minimum length limit and the daily bag limit is unlimited. | — |
| Rough Fish | Open All Year | No minimum length limit and the daily bag limit is unlimited. | — |
| Round Goby | Open All Year | The daily bag limit is 0, one may be killed and possessed for transport to a WDNR Office. | — |
| Ruffe | Open All Year | The daily bag limit is 0, one may be killed and possessed for transport to a WDNR Office. | — |
| Shovelnose Sturgeon | Closed | No fishing allowed. | — |
| Trout | See specific regulations | https://dnr.wisconsin.gov/topic/fishing/trout/ . | — |
| Walleye, Sauger, And Hybrids | May 2, 2026 to March 7, 2027 | The minimum length limit is 15" and the daily bag limit is 3. | — |
| White Perch | Open All Year | The daily bag limit is 0, one may be killed and possessed for transport to a WDNR Office. | — |
Regulations sourced from Wisconsin DNR fisheries data. Always verify current regulations before fishing.
Lake Details
- WBIC
- 776400
- County
- Columbia County
- Surface Area
- 250 acres
- Lake Type
- lake
- Coordinates
- 43.4242, -89.1697
Boat Rentals Nearby
Pontoon
Listing soonFishing Boat + Motor
Listing soonKayak / Canoe
Listing soonKnow a local boat rental operator near Grassy Lake? Let us know.
Boat Landings (1)
NA · NA
Lake data sourced from the Wisconsin DNR. Last updated 4/30/2026.