Minnesota · Isanti County
Blue Lake Fishing guide
Blue Lake covers 296 acres in Isanti County, Minnesota, reaching 31 ft at its deepest point. Secchi readings average around 4.4 ft of visibility. The Minnesota DNR has surveyed the lake 11 times, most recently in 2025, with walleye, largemouth bass, northern pike and bluegill in the nets.
DNR survey data
Fish species
WalleyeLast stocked 2024Good numbers5.3per gill net20"Typical23"Biggest
Lengths measured · 32 fish
Recent · 2021Lengths measured · 32 fish
2021Lengths measured · 31 fish
2013Lengths measured · 19 fish
2009Lengths measured · 11 fish
2004Largemouth bassGood numbers60.6per hr (electrofishing)12"Typical19"Biggest
Lengths measured · 54 fish
Recent · 2021Lengths measured · 54 fish
2021Lengths measured · 82 fish
2013Lengths measured · 74 fish
2009Lengths measured · 61 fish
2004Northern pikeJust a few1.7per gill net27"Typical37"Biggest
Lengths measured · 10 fish
Recent · 2021Lengths measured · 10 fish
2021Lengths measured · 18 fish
2013Lengths measured · 7 fish
2009Only 7 fish measured that year — too few to read as a shape.
Lengths measured · 8 fish
2004Only 8 fish measured that year — too few to read as a shape.
BluegillJust a few18.7per trap net6"Typical9"Biggest
Lengths measured · 753 fish
Recent · 2021 + 2024Lengths measured · 480 fish
2024Lengths measured · 273 fish
2021Lengths measured · 171 fish
2013Lengths measured · 152 fish
2009CrappieJust a few5.7per trap net9"Typical11"Biggest
Lengths measured · 499 fish
Recent · 2021 + 2024 + 2025Lengths measured · 264 fish
2025Lengths measured · 172 fish
2024Lengths measured · 63 fish
2021Lengths measured · 44 fish
2013Yellow perchFair numbers4per gill net6"Typical8"Biggest
Lengths measured · 34 fish
Recent · 2021Lengths measured · 34 fish
2021Lengths measured · 70 fish
2013Lengths measured · 208 fish
2009Lengths measured · 182 fish
2004Rates 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 Blue 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.
- 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.
- 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 |
|---|---|---|---|
| 2021 | 23" | 19" | 37" |
| 2013 | 26" | 18" | 27" |
| 2009 | 29" | 19" | 25" |
| 2004 | 25" | 20" | 30" |
| 1999 | 23" | 18" | 37" |
| 1994 | 26" | 17" | 31" |
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 · Hardbaits
Topwater Popper
2.5–3" concave-face popper
Largemouth bass · Hardbaits
Hollow-Body Frog
3–3.5" hollow-body frog
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.
DNR stocking records
Stocking history
| Year | Species | Stocked |
|---|---|---|
| 2024 | Walleye | 2,058 fingerlings |
| 2022 | Walleye | 8,576 fingerlings |
| 2020 | Walleye | 4,690 yearlings |
| 2018 | Walleye | 3,189 fingerlings |
| 2016 | Walleye | 585 fingerlings · 246 yearlings · 5 adults |
MN DNR · in their words
From the 2025 survey
Blue Lake is a 263-acre lake in southwest Isanti County located five miles northeast of Zimmerman and is within the Rum River watershed. It has a maximum depth of 31 feet and 51 percent of the lake is less than 15 feet deep (134 acres). Water clarity in May and June can be 6 to 9 feet; however, it becomes low in summer and ranges from 3 to 5 feet as algal blooms become present. An aquatic vegetation survey in 2021 indicated vegetation was present in depths up to 15 feet, but most common in depths from 1 to 9 feet. Blue Lake was found to have a low diversity of aquatic plants, with 10 submergent and 4 floating leaf species sampled lake wide. The diversity of aquatic plants has declined throughout the nine surveys that have occurred since 2004. Boat navigation during early summer can be affected by dense stands of Curly leaf pondweed in shallow areas, which is a non-native species. The most common shoreline substrate is sand, followed by gravel and muck, which results in abundant spawning habitat for bluegills and crappies. There are two public accesses located on the lake, one in the middle of the eastern shore and one on the northwestern shore. Parking is limited at both accesses. The lake is well developed and popular with local pleasure boaters.
Past standard lake surveys on Blue Lake have occurred in August. Warm summer water temperatures typically result in crappies suspending in open water, which decreases their sampling efficiency. No prior crappie or bluegill spawning surveys have occurred on Blue Lake until 2024. In 2024 a survey targeting spawning bluegills was conducted which included trap netting from May 14 -17 when water temperatures ranged from 62 to 65 degrees.
Read the full DNR narrative
In the 2024 targeted bluegill survey, a total of 172 Black Crappie were sampled for a catch rate of 6.6/net. Black crappie lengths ranged from 4.0 to 10.8 inches with an average length of 7.4 inches. Ten percent of crappies sampled were greater than 10 inches. The 2024 survey demonstrated a good crappie population was present; however, aging structures were not taken. Therefore, to include Blue Lake in the statewide crappie research project, electrofishing was used in 2025 to sample known crappie areas efficiently.
In the spring of 2025, a targeted Crappie survey was done to assess the crappie population and occurred in conjunction with a statewide crappie research study. Fish were collected using an electrofishing boat on May 12th with a water surface temp of 64 degrees. A total of 264 Black Crappies were caught. Shocking was done along the shoreline intermittently and stations were not standardized so catch rate comparisons from this survey are not appropriate. Crappies ranged from 3.7 to 11.4 inches, with an average length of 9.0 inches. Thirty-six percent of crappies were 10 inches or greater. A total of 110 of the crappies were aged using otoliths. All fish sampled were between ages 2 and 6, except one age-10 fish. The 2020-year class was the most frequently sampled (age-5), comprising 48% of the sample.
Narrative text from the Minnesota DNR lake survey.
Recent reports
Blue Lake fishing reports
Recent reports on Blue 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
- Blue Lake (NW) (trailer launch)
- Blue Lake (SE) (trailer launch)
DNR bathymetry
Blue Lake depth map
Within 30 miles
Nearby lakes
- Sandy Lake · 64 ac · 1.1 mi
- Baxter Lake · 89 ac · 1.8 mi
- West Hunter Lake · 61 ac · 3.2 mi
- East Hunter Lake · 57 ac · 3.4 mi
- Fremont Lake · 493 ac · 4.1 mi
- Elk Lake · 362 ac · 6.1 mi
- Green Lake · 833 ac · 7.3 mi
- Long Lake · 387 ac · 7.5 mi
Quick answers
Frequently asked questions
How deep is Blue Lake?
Blue Lake reaches 31 ft at its deepest point; about 45% of the lake is littoral (15 ft or shallower).
How big is Blue Lake?
Blue Lake covers 296 acres with about 6.4 miles of shoreline.
How clear is the water in Blue Lake?
DNR Secchi readings on Blue Lake average 4.4 ft of visibility, middling clarity for a Minnesota lake.
What fish are in Blue Lake?
Minnesota DNR surveys (most recently 2025) record walleye, largemouth bass, northern pike, bluegill, crappie, yellow perch.
Is Blue Lake stocked?
Yes. The DNR stocked walleye in 2024; the stocking table on this page lists every year back to 2016.
Does Blue Lake have a public access?
Yes. Blue Lake has 2 public access sites, including Blue Lake (NW) (trailer launch).
How big do walleye get in Blue Lake?
The biggest walleye measured in recent DNR surveys taped 23"; the size-history table on this page tracks the biggest fish in each survey back to 1994.
When was Blue Lake last surveyed?
The Minnesota DNR last surveyed Blue Lake in 2025, the most recent of 11 surveys on record.
Page updated .
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