Minnesota · Crow Wing County
O'Brien Lake Fishing guide
O'Brien Lake covers 186 acres in Crow Wing County, Minnesota, reaching 49 ft at its deepest point. Average water clarity runs about 24 ft. The Minnesota DNR has surveyed the lake 9 times, most recently in 2024, with walleye, largemouth bass, smallmouth bass and northern pike in the nets.
DNR survey data
Fish species
BluegillFair numbers29.7per trap net7"Typical10"Biggest
Lengths measured · 267 fish
Recent · 2024Lengths measured · 267 fish
2024Lengths measured · 164 fish
2019Lengths measured · 91 fish
2012Lengths measured · 409 fish
1999Rates 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 O'Brien 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 24 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 49 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 24 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 49 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 | Smallmouth bass |
|---|---|---|---|
| 2024 | 11" | 18" | — |
| 2019 | 18" | 25" | — |
| 2012 | 16" | — | — |
| 1999 | 14" | 23" | — |
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
Smallmouth bass · Soft plastics
Drop Shot (Finesse Plastic)
4" finesse worm or 3" minnow-profile plastic
Smallmouth bass · Jigs & bladed
Tail Spinner
Compact lead body with a free-spinning blade on the tail
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 | 3,090 fingerlings |
| 2024 | Yellow Perch | 2,640 fingerlings |
| 2020 | Walleye | 1,620 fingerlings |
| 2016 | Walleye | 650 fingerlings |
MN DNR · in their words
From the 2024 survey
A summer trap net survey was conducted in O'Brien Lake by IBI Program staff beginning on June 10, 2024. Nine trap nets were set along the shoreline in locations that encompassed multiple habitat types. Trap net sampling captured 10 species of fish, including 1 species that is intolerant of disturbance (Rock Bass). Bluegill comprised a majority of the catch both by number and by biomass. Pumpkinseed and Yellow Bullhead were also numerous. Bowfin, although few in number, comprised a significant proportion of the catch by biomass.
The trap net survey data was combined with a targeted survey of nearshore fish species in O'Brien Lake conducted in August of 2022. Nearshore sampling captured 19 species of fish, including 7 species that are intolerant of disturbance (Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter, Least Darter, Rock Bass, and Smallmouth Bass) and 1 species that is tolerant of disturbance (Green Sunfish).
Read the full DNR narrative
The nearshore and trap net data were combined with gill net data from a survey conducted in June of 2019 to describe the fish community and provide a fish-based IBI (FIBI) score. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (e.g., Blackchin Shiner, Iowa Darter, and Rock Bass), while other species are tolerant of degraded conditions (e.g., Green Sunfish and Common Carp). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website.
This survey, and the corresponding nearshore and gill net surveys, provide evidence that the fish community in O'Brien Lake is healthy as indicated by an FIBI score that exceeds the exceptional use threshold determined for similar lakes. The survey results will be considered when the biological health of the lake is assessed during the Pine River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.
O'Brien Lake provides recreational angling opportunities for sunfish, Largemouth Bass, Northern Pike, and Walleye. Although uncommon, Smallmouth Bass are also present in O'Brien Lake. O'Brien Lake provides habitat for the Least Darter, a species of special concern in Minnesota. Least Darters rely on aquatic vegetation and high-quality shoreline habitat to carry out their life cycles. You can help protect the Least Darter and other fish in O'Brien Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.
Narrative text from the Minnesota DNR lake survey.
Recent reports
O'Brien Lake fishing reports
Recent reports on O'Brien 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
- O'Brien Lake (trailer launch)
DNR bathymetry
O'Brien Lake depth map
Within 30 miles
Nearby lakes
- Velvet Lake · 167 ac · 1 mi
- Goodrich Lake · 382 ac · 1.1 mi
- Dolney Lake · 272 ac · 1.7 mi
- Command Lake · 21 ac · 1.9 mi
- Little Pine Lake · 330 ac · 2.5 mi
- Greer Lake · 354 ac · 2.6 mi
- Daggett Lake · 258 ac · 2.7 mi
- Pickerel Lake · 117 ac · 3 mi
Quick answers
Frequently asked questions
How deep is O'Brien Lake?
O'Brien Lake reaches 49 ft at its deepest point; about 55% of the lake is littoral (15 ft or shallower).
How big is O'Brien Lake?
O'Brien Lake covers 186 acres with about 4.7 miles of shoreline.
How clear is the water in O'Brien Lake?
DNR Secchi readings on O'Brien Lake average 24 ft of visibility, clear water for a Minnesota lake.
What fish are in O'Brien Lake?
Minnesota DNR surveys (most recently 2024) record walleye, largemouth bass, smallmouth bass, northern pike, bluegill, crappie, yellow perch, rock bass.
Is O'Brien Lake stocked?
Yes. The DNR stocked walleye and yellow perch in 2024; the stocking table on this page lists every year back to 2016.
Does O'Brien Lake have a public access?
Yes. O'Brien Lake has one public access site: O'Brien Lake (trailer launch).
How big do largemouth bass get in O'Brien Lake?
The biggest largemouth bass measured in recent DNR surveys taped 11"; the size-history table on this page tracks the biggest fish in each survey back to 1999.
When was O'Brien Lake last surveyed?
The Minnesota DNR last surveyed O'Brien Lake in 2024, the most recent of 9 surveys on record.
Page updated .
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