Minnesota · Cass County
Blackwater Lake Fishing guide
Blackwater Lake covers 772 acres in Cass County, Minnesota, reaching 67 ft at its deepest point. Secchi readings average around 12.5 ft of visibility. The Minnesota DNR has surveyed the lake 13 times, most recently in 2023, with walleye, largemouth bass, smallmouth bass and northern pike in the nets.
DNR survey data
Fish species
WalleyeLast stocked 2024Fair numbers2per gill net19"Typical27"Biggest
Lengths measured · 26 fish
Recent · 2023Lengths measured · 26 fish
2023Lengths measured · 24 fish
2019Lengths measured · 40 fish
2015Lengths measured · 48 fish
2011Largemouth bassGood numbers59.9per hr (electrofishing)9"Typical17"Biggest
Lengths measured · 160 fish
Recent · 2023Lengths measured · 160 fish
2023Lengths measured · 125 fish
2019Lengths measured · 1144 fish
2015Lengths measured · 688 fish
2011Smallmouth bassJust a few3.5per hr (electrofishing)13"Typical20"Biggest
Lengths measured · 16 fish
Recent · 2023Lengths measured · 16 fish
2023Lengths measured · 10 fish
2019Lengths measured · 163 fish
2015Lengths measured · 68 fish
2011Northern pikeFair numbers9.8per gill net21"Typical35"Biggest
Lengths measured · 118 fish
Recent · 2023Lengths measured · 118 fish
2023Lengths measured · 152 fish
2019Lengths measured · 95 fish
2015Lengths measured · 135 fish
2011BluegillJust a few7.5per trap net6"Typical9"Biggest
Lengths measured · 113 fish
Recent · 2023Lengths measured · 113 fish
2023Lengths measured · 290 fish
2019Lengths measured · 286 fish
2015Lengths measured · 145 fish
2011CrappieJust a few0.5per trap net8"Typical12"Biggest
Lengths measured · 16 fish
Recent · 2023Lengths measured · 16 fish
2023Lengths measured · 9 fish
2019Only 9 fish measured that year — too few to read as a shape.
Lengths measured · 33 fish
2015Lengths measured · 8 fish
2011Only 8 fish measured that year — too few to read as a shape.
Yellow perchFair numbers1.7per gill net6"Typical8"Biggest
Lengths measured · 20 fish
Recent · 2023Lengths measured · 20 fish
2023Lengths measured · 20 fish
2019Lengths measured · 29 fish
2015Lengths measured · 60 fish
2011Rock bassGood numbers1.3per trap net5"Typical9"Biggest
Lengths measured · 43 fish
Recent · 2023Lengths measured · 43 fish
2023Lengths measured · 48 fish
2019Lengths measured · 48 fish
2015Lengths measured · 48 fish
2011Rates come from standard DNR survey gear (gill nets, trap nets, electrofishing), judged against statewide benchmarks for the same gear, so the same number of fish per net can read differently for two species. Where the standard gear can't count a species reliably, only presence and size are listed. Typical is the middle fish of those measured. Open a row for the full length spread, survey by survey.
How to fish Blackwater Lake through the year
Largemouth bass
- Spring
- Largemouth are moving up into the warming bays and flats, staging around wood, docks and new weeds to spawn. At 12.5 ft of clarity, fish them deeper and lighter than usual.
- Early summer
- Largemouth are on the shallow spawning flats and protected bays, where beds go on firm bottom next to isolated cover.
- Summer
- Largemouth are in and along the weeds: cabbage and milfoil edges, matted cover and shade. On a lake that drops to 67 ft, check the deep edge of that structure too.
- Fall
- Largemouth are chasing bait back onto the flats and into the remaining green weeds, feeding hard and shallow before the freeze.
Walleye
- Spring
- Walleye are shallow, on and just off the spawning flats and the first green weeds. At 12.5 ft of clarity, fish them deeper and lighter than usual.
- Early summer
- Walleye are setting up on the outside weed edge, points and shallow structure.
- Summer
- Walleye are working the weed edge, points and any wind-blown structure. On a lake that drops to 67 ft, check the deep edge of that structure too.
- Fall
- Walleye are packing onto the sharpest breaks and points as the water cools, in big schools with short windows.
Season patterns for each species. Open the live map for today's wind, light and water temp.
Size history
Biggest fish by survey year
| Survey year | Largemouth bass | Walleye | Northern pike |
|---|---|---|---|
| 2023 | 17" | 27" | 35" |
| 2019 | 17" | 23" | 32" |
| 2015 | 20" | 24" | 30" |
| 2011 | 20" | 27" | 30" |
| 2008 | 17" | 27" | 28" |
| 2004 | 20" | 24" | 34" |
| 2001 | 19" | 24" | 32" |
| 1997 | 14" | 28" | 37" |
Longest fish measured by DNR survey crews in each year's nets. Survey gear samples the population, so the lake usually holds larger fish than any survey measured.
Suggested tackle
What to bring
Top presentations for this lake's structure and clarity:
Largemouth bass · Soft plastics
Texas-Rigged Worm
7" ribbon-tail or straight-tail plastic worm
Largemouth bass · Soft plastics
Free Rig
Creature bait or magnum finesse worm
Walleye · Live bait
Live-Bait (Lindy) Rig + Leech/Crawler
jumbo leech or half a nightcrawler
Walleye · Trolling
Leadcore Line + Crankbaits
4–5" mid-diving crankbait behind a long leadcore run
Northern pike · Soft plastics
Paddletail Swimbait on Jighead
4–5" paddletail swimbait on a ball-head swimbait jighead
Northern pike · Jigs & bladed
Inline Spinner (Mepps/Blue Fox)
#2–#4 in-line spinner
Full setups, including hooks, weights and line, are on the live map. As an Amazon Associate I earn from qualifying purchases.
DNR stocking records
Stocking history
| Year | Species | Stocked |
|---|---|---|
| 2024 | Walleye | 4,802 fingerlings |
| 2022 | Walleye | 5,776 fingerlings |
| 2021 | Walleye | 2,688 yearlings |
| 2020 | Walleye | 357 yearlings |
| 2018 | Walleye | 5,880 fingerlings |
| 2016 | Walleye | 18,171 fingerlings |
MN DNR · in their words
From the 2023 survey
Blackwater Lake is a 767-acre lake with 7.6 miles of shoreline and a maximum depth of 67 feet located southwest of Longville, MN. A DNR owned public access is located on the northeast shore. The DNR has classified Minnesota's lakes into 43 different classes based on physical, chemical, and other characteristics. Blackwater Lake is in Lake Class 25; lakes in this class are characterized as Sunfish waters. Other area lakes in this class include Boy, Girl, Hand, Inguadona, Long, and Swift Lakes. Blackwater Lake possesses a highly developed shoreline. The lake is primarily managed for Largemouth Bass, Smallmouth Bass, Northern Pike, and Walleye and secondarily for Black Crappie, Bluegill, Tullibee (Cisco), and Yellow Perch. An experimental catch and release regulation for Largemouth and Smallmouth Bass implemented in 2004 was modified to a 14-20-inch protected slot limit with 1 over 20 in 2016. The regulation was removed in 2021.
Largemouth and Smallmouth Bass in Blackwater Lake provide angling opportunity for quality fish of both species. Largemouth Bass are most abundant and ranged in length from 5 to 18 inches. Smallmouth Bass are present in lower numbers and fish up to 20 inches long were sampled. Northern Pike are abundant in the lake, exceeding the maximum management goal. Sampled pike ranged from 11 to 36 inches long, averaging 22 inches. Walleye abundance in the lake is low despite fingerling stocking efforts. Walleye lengths ranged from 14 to 28 inches and averaged 20 inches long. Bluegill catch rates fell below the target management range, though exceeded size goals. Black Crappie up to 13 inches were sampled. Tullibee (Cisco) have been present in the catch since initial surveying and catch rates exceeded the management goal in 2023. Yellow Perch abundance has remained low across historical surveys.
Read the full DNR narrative
Other fish species that anglers can expect to encounter in Blackwater Lake include, Brown Bullhead, Hybrid Sunfish, Pumpkinseed, Rock Bass, Bowfin, White Sucker, and Yellow Bullhead.
People can have significant impacts on lakes and the fish populations they support. Harvest, lakeshore development, removal of shoreline vegetation, and introductions of invasive species can all adversely affect fish populations. Currently, Rusty Crayfish are the only aquatic invasive species (AIS) that have been identified in Blackwater Lake. AIS are moved from infested to non-infested waters by anglers, boaters, and lake shore owners and can adversely impact lakes and fish populations. To avoid spreading AIS, lake users are required to remove all aquatic plants or animals from their watercraft and drain all water from their boat before leaving the access. If you suspect an infestation of an invasive species in this lake, save a specimen and report it to a local natural resource office. Additional information on all of these topics can be found on the DNR website (www.dnr.state.mn.us) or by contacting the Walker Area Fisheries office.
Narrative text from the Minnesota DNR lake survey.
Recent reports
Blackwater Lake fishing reports
Recent reports on Blackwater Lake from guides, tournaments and regular anglers. Anything posted in the last two weeks also bumps the matching spots on the live map, so you'll see a "matches a recent report" tag on them.
Public water access
Getting on the water
- Black Water Lake (trailer launch)
DNR bathymetry
Blackwater Lake depth map
Within 30 miles
Nearby lakes
- Widow Lake · 198 ac · 1.5 mi
- Island Lake · 184 ac · 1.6 mi
- Sand Lake · 41 ac · 1.7 mi
- Sand Lake · 149 ac · 1.8 mi
- Mule Lake · 525 ac · 2.2 mi
- Ponto Lake · 388 ac · 2.9 mi
- Hay Lake · 364 ac · 3 mi
- Long Lake · 246 ac · 3 mi
Quick answers
Frequently asked questions
How deep is Blackwater Lake?
Blackwater Lake reaches 67 ft at its deepest point; about 44% of the lake is littoral (15 ft or shallower).
How big is Blackwater Lake?
Blackwater Lake covers 772 acres with about 7.7 miles of shoreline.
How clear is the water in Blackwater Lake?
DNR Secchi readings on Blackwater Lake average 12.5 ft of visibility, clear water for a Minnesota lake.
What fish are in Blackwater Lake?
Minnesota DNR surveys (most recently 2023) record walleye, largemouth bass, smallmouth bass, northern pike, bluegill, crappie, yellow perch, rock bass.
Is Blackwater Lake stocked?
Yes. The DNR stocked walleye in 2024; the stocking table on this page lists every year back to 2016.
Does Blackwater Lake have a public access?
Yes. Blackwater Lake has one public access site: Black Water Lake (trailer launch).
How big do largemouth bass get in Blackwater Lake?
The biggest largemouth bass measured in recent DNR surveys taped 17"; the size-history table on this page tracks the biggest fish in each survey back to 1997.
When was Blackwater Lake last surveyed?
The Minnesota DNR last surveyed Blackwater Lake in 2023, the most recent of 13 surveys on record.
Page updated .
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