Minnesota · Cass County
Little Thunder Lake Fishing guide
Little Thunder Lake sits in Cass County, Minnesota, and covers 258 acres, reaching 72 ft at its deepest point. Secchi readings average around 9.8 ft of visibility. The Minnesota DNR has surveyed the lake 7 times, most recently in 2025, with walleye, largemouth bass, northern pike and bluegill in the nets.
DNR survey data
Fish species
Northern pikeJust a few1.8per gill net19"Typical28"Biggest
Lengths measured · 20 fish
Recent · 2024 + 2025Lengths measured · 7 fish
2025Only 7 fish measured that year — too few to read as a shape.
Lengths measured · 13 fish
2024Lengths measured · 6 fish
2014Only 6 fish measured that year — too few to read as a shape.
Lengths measured · 26 fish
2009BluegillJust a few6.6per trap net5"Typical8"Biggest
Lengths measured · 106 fish
Recent · 2024 + 2025Lengths measured · 50 fish
2025Lengths measured · 56 fish
2024Lengths measured · 27 fish
2014Lengths measured · 62 fish
2009CrappieJust a few0.6per trap net9"Typical10"Biggest
Lengths measured · 10 fish
Recent · 2024 + 2025Lengths measured · 2 fish
2025Only 2 fish measured that year — too few to read as a shape.
Lengths measured · 8 fish
2024Only 8 fish measured that year — too few to read as a shape.
Lengths measured · 5 fish
2014Only 5 fish measured that year — too few to read as a shape.
Lengths measured · 8 fish
2009Only 8 fish measured that year — too few to read as a shape.
Yellow perchFair numbers1.8per gill net5"Typical6"Biggest
Lengths measured · 13 fish
Recent · 2024 + 2025Lengths measured · 1 fish
2025Only 1 fish measured that year — too few to read as a shape.
Lengths measured · 12 fish
2024Lengths measured · 5 fish
2009Only 5 fish measured that year — too few to read as a shape.
Lengths measured · 9 fish
2002Only 9 fish measured that year — too few to read as a shape.
Rates 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 Little Thunder Lake through the year
Walleye
- Spring
- Walleye are shallow, on and just off the spawning flats and the first green weeds.
- 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 72 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.
Largemouth bass
- Spring
- Largemouth are moving up into the warming bays and flats, staging around wood, docks and new weeds to spawn.
- 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 72 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.
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 | Walleye | Largemouth bass | Northern pike |
|---|---|---|---|
| 2025 | — | — | 22" |
| 2024 | 19" | — | 28" |
| 2014 | — | 4" | 31" |
| 2009 | — | — | 31" |
| 2002 | — | 1" | 35" |
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:
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
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
Northern pike · Soft plastics
Paddletail Swimbait on Jighead
4–5" paddletail swimbait on a ball-head swimbait jighead
Northern pike · Muskie & pike
Soft Rubber (Bull Dawg / Medusa)
10" soft rubber body bait
Full setups, including hooks, weights and line, are on the live map. As an Amazon Associate I earn from qualifying purchases.
MN DNR · in their words
From the 2025 survey
A targeted survey of nearshore fish species in Little Thunder Lake was conducted beginning on August 11, 2025, by Lake Biological Monitoring and Assessment (LBMA) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack electrofishing was completed at 10 sampling stations. Similarly, a 50-foot seine was used to sample seven stations, and a 15-foot seine was used at one station. Two stations were electrofished from the boat and not seined because they were located along a bog or cattail fringe. Nearshore sampling captured 16 species of fish including 6 species that are intolerant of disturbance (i.e., Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter, Least Darter, Northern Sunfish) and none that are tolerant of disturbance.
A concurrent summer trap net survey was also conducted by LBMA Program staff. Eight trap nets were set along the shoreline in locations that encompassed multiple habitat types. Trap net sampling captured 10 species of fish, including one that is intolerant of disturbance (i.e., Rock Bass) and none that are tolerant of disturbance. Bluegill comprised a majority of the catch by number and whereas Bowfin comprised a majority by biomass.
Read the full DNR narrative
The nearshore and trap net data were combined with gill net data from a survey conducted during the week of June 10, 2024 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., 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.
Results from this survey provide evidence that the fish community in Little Thunder Lake is healthy as indicated by an FIBI score that exceeds the exceptional aquatic life use threshold determined for similar lakes. The FIBI results are similar to previous findings, which indicated that Little Thunder Lake is fully supporting aquatic life use. The survey results will be considered when the biological health of the lake is assessed during the Mississippi River-Grand Rapids Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency. You can help protect the fish community in Little Thunder Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species.
Narrative text from the Minnesota DNR lake survey.
Recent reports
Little Thunder Lake fishing reports
Recent reports on Little Thunder 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
- DNR access: Southwest corner of lake.
DNR bathymetry
Little Thunder Lake depth map
Within 30 miles
Nearby lakes
- Thunder Lake · 1,347 ac · 5.1 mi
- Bass Lake · 195 ac · 5.9 mi
- Holy Water Lake · 94 ac · 6.7 mi
- Little Bass Lake · 136 ac · 6.8 mi
- Third Guide Lake · 40 ac · 7.3 mi
- Upper Trelipe Lake · 421 ac · 8.1 mi
- Big Sand Lake · 731 ac · 8.2 mi
- Island Lake · 358 ac · 8.7 mi
Quick answers
Frequently asked questions
How deep is Little Thunder Lake?
Little Thunder Lake reaches 72 ft at its deepest point with a mean depth of 29 ft; about 31% of the lake is littoral (15 ft or shallower).
How big is Little Thunder Lake?
Little Thunder Lake covers 258 acres with about 6.2 miles of shoreline.
How clear is the water in Little Thunder Lake?
DNR Secchi readings on Little Thunder Lake average 9.8 ft of visibility, middling clarity for a Minnesota lake.
What fish are in Little Thunder Lake?
Minnesota DNR surveys (most recently 2025) record walleye, largemouth bass, northern pike, bluegill, crappie, yellow perch, rock bass.
Is Little Thunder Lake stocked?
No stocking is on record for Little Thunder Lake in the DNR's stocking database.
Does Little Thunder Lake have a public access?
Yes. Little Thunder Lake has one public access site: DNR access (Southwest corner of lake.).
How big do walleye get in Little Thunder Lake?
The biggest walleye measured in recent DNR surveys taped 19"; the size-history table on this page tracks the biggest fish in each survey back to 2002.
When was Little Thunder Lake last surveyed?
The Minnesota DNR last surveyed Little Thunder Lake in 2025, the most recent of 7 surveys on record.
Page updated .
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