Blackwater Lake
About Blackwater Lake
Blackwater Lake is a 771-acre lake near Longville in Cass County, Minnesota. It reaches 67 feet at its deepest point, and has roughly 7.7 miles of shoreline. DNR surveys put average water clarity at about 12.5 feet, clearer than most lakes in the state.
Minnesota DNR fisheries surveys list 16 fish species here, including walleye, northern pike, largemouth bass, smallmouth bass, black crappie, and bluegill. The DNR has stocking records for the lake, so check the stocking report for the most recent species and year classes. The most recent fisheries survey on file dates to 2023.
There is one public boat launch (concrete surface) managed by the Minnesota DNR. Ice typically goes out around April 17, based on 22 years of DNR ice-out records.
Plan Your Visit to Blackwater Lake
- 771 acres, up to 67 feet deep, near Longville
- 1 public boat launch (concrete) — managed by the Minnesota DNR
- Game fish on the DNR survey: walleye, northern pike, largemouth bass, smallmouth bass, black crappie, and bluegill
- Average water clarity around 12.5 feet — very clear
Access & Fees
- Public access
- 1 public boat launch (concrete)
- Launch fee
- Free at DNR accesses
- Managed by
- Minnesota DNR
Conditions
- Surface area
- 771 acres
- Max depth
- 67 ft
- Shoreline
- 7.7 mi
- Water clarity
- 12.5 ft
- Shallows (under 15 ft)
- 336 acres
Rules & Regulations
- A Minnesota fishing license is required for anglers 16 and older
- Drain plugs must be out and all water drained before leaving any access; remove aquatic plants from boats and trailers
- Children under 10 must wear a life jacket on a boat that is underway
Facilities
- 1 public boat launch (concrete)
Best For
- Walleye fishing
- Quiet paddling
- Ice fishing
- Ice is never completely safe — check thickness yourself before walking or driving on any lake
Angler's Report
Minnesota DNR LakeFinder- Species on survey
- 16
- Game fish
- 10
- Stocked
- Yes
- Last DNR survey
- 2023
- Special regulations
- No
- Fishing pier
- No
- Ice fishing
- Yes
- Boat launch
- Yes
Fishing data: Minnesota Department of Natural Resources. Regulations change — confirm with the current DNR fishing regulations.
Ice-Out History
- Median ice-out
- April 17
- Years of record
- 22
- Earliest
- March 25, 2012
- Latest
- May 13, 2013
- Most recent
- May 7, 2022
See every lake on the ice-out tracker. Ice-out data: Minnesota DNR State Climatology Office.
Activities
Amenities
Fish Species
Plan your trip to Blackwater Lake
Compare Blackwater Lake against the top-ranked lakes nearby, then map your route.
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See how Blackwater Lake ranks among ice fishing lakes nearby.
Nearby Lakes
Widow Lake
64 out of 100 Lake ScoreCass · Longville198 acres
1.5 miles away
Island Lake
63 out of 100 Lake ScoreCass · Longville184 acres
1.6 miles away
Sand Lake
40 out of 100 Lake ScoreCass · Longville41 acres
1.7 miles away
Sand Lake
64 out of 100 Lake ScoreCass · Hackensack149 acres
1.7 miles away
Mule Lake
66 out of 100 Lake ScoreCass · Longville525 acres
1.9 miles away
Long Lake
61 out of 100 Lake ScoreCass · Hackensack246 acres
2.8 miles away
Frequently Asked Questions
Where is Blackwater Lake?
Blackwater Lake is in Cass County, Minnesota, near Longville. It covers 771 acres and reaches 67 feet deep.
How big and how deep is Blackwater Lake?
Blackwater Lake covers 771 acres with about 7.7 miles of shoreline. Its maximum depth is 67 feet.
What fish can you catch at Blackwater Lake?
Minnesota DNR surveys list Walleye, Northern Pike, Largemouth Bass, Smallmouth Bass, Black Crappie, Bluegill, Pumpkinseed, Yellow Perch, and Tullibee (Cisco) and other species. A Minnesota fishing license is required for anyone 16 and older.
Is there a public boat launch on Blackwater Lake?
Yes. Blackwater Lake has 1 public boat launch (concrete), managed by the Minnesota DNR. DNR public water accesses are free to use.
Can you swim at Blackwater Lake?
There is no mapped public swim beach at Blackwater Lake. Minnesota's public waters are open to swimming where you have legal access, but there are no lifeguards or water-quality monitoring away from designated beaches.
Is Blackwater Lake stocked?
Yes. The Minnesota DNR has stocking records for Blackwater Lake; species and numbers vary by year, so see the stocking report on DNR LakeFinder.
When does the ice go out on Blackwater Lake?
The median ice-out date is April 17, from 22 years of Minnesota DNR records. The earliest on record is March 25, 2012 and the latest is May 13, 2013.