Minnesota · Douglas County
North Union Lake Fishing guide
North Union Lake covers 118 acres in Douglas County, Minnesota, reaching 42 ft at its deepest point. Secchi readings average around 15 ft of visibility. The Minnesota DNR has surveyed the lake 7 times, most recently in 2018, with walleye, largemouth bass, northern pike and bluegill in the nets. That survey is 8 years old now.
DNR survey data
Fish species
Northern pikeFair numbers9.5per gill net19"Typical24"Biggest
Lengths measured · 21 fish
Recent · 2018Lengths measured · 21 fish
2018Lengths measured · 17 fish
2008Lengths measured · 14 fish
2002Lengths measured · 19 fish
1997BluegillJust a few17.3per trap net7"Typical8"Biggest
Lengths measured · 73 fish
Recent · 2018Lengths measured · 73 fish
2018Lengths measured · 123 fish
2008Lengths measured · 148 fish
2002Lengths measured · 403 fish
1997Rates 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 North Union Lake through the year
Walleye
- Spring
- Walleye are shallow, on and just off the spawning flats and the first green weeds. At 15 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 42 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.
Northern pike
- Spring
- Pike are in the shallow bays and along new weed growth. At 15 ft of clarity, fish them deeper and lighter than usual.
- Early summer
- Pike are on the outside weed edge and points.
- Summer
- Pike are on the deep weed edge and points near the coolest water they can find. On a lake that drops to 42 ft, check the deep edge of that structure too.
- Fall
- Pike are on the last green weeds and the breaks beside them, feeding heavily as the water drops.
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 | Northern pike | Largemouth bass |
|---|---|---|---|
| 2018 | 19" | 24" | 14" |
| 2008 | 23" | 25" | 8" |
| 2002 | 23" | 26" | 16" |
| 1997 | 28" | 30" | 15" |
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
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
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
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 2018 survey
North Union, Stony, and Lottie (Taylor) lakes form a chain of lakes between Brophy and Cowdry Lakes in Douglas County. North Union Lake is the upper or first lake in this chain of interconnected lakes. Brophy Lake discharges into North Union. North Union outlets to Stony Lake. None of these three small basins have public landings, but anglers can utilize access sites on Cowdry and Brophy Lakes and navigate small watercraft throughout the chain via flowage channels. Access to these lakes with larger, high profile boats is constrained by bridge crossings and road culverts.
The lakes in this chain are small and relatively unique in that shoreline development has been limited and much of the natural shoreline remains intact. Water quality and clarity are very good. Water transparency at time of the August survey was measured at 19.0 feet. Near-shore areas support lush vegetative growth including bulrushes and water lilies. These habitat characteristics are ideal for Northern Pike, Largemouth Bass, and Bluegill.
Read the full DNR narrative
Bluegills are abundant in North Union and accounted for most of the total gamefish catch. Average size of Bluegills caught in trap nets was 6.8 inches. The largest Bluegill captured measured 8.4 inches. Ten percent of the total catch of Bluegills were 8.0 inches and larger. Black Crappie catches were low, but crappies are typically difficult to catch in mid-summer surveys. Crappies are anticipated to be more abundant than reflected in survey catch statistics. The largest Black Crappie caught in the survey was 10.1 inches long. Northern Pike are abundant in North Union Lake, though most of the fish caught in the survey were small. Average length of pike captures was 19.6 inches long. Navigation restrictions prevented access with an electrofishing boat to survey the Largemouth Bass population. Only a few Largemouth Bass were caught in the survey nets. Habitat conditions are excellent for Largemouth Bass and this popular gamefish is projected to be abundant.
Anglers and other outdoor recreationists looking for a quiet lake should check out the North Union, Stony, and Lottie lake chain. This chain of lakes provides a remote lake setting in close proximity to the city of Alexandria. Lake Brophy County Park is currently in development and will encompass the West side of North Union Lake. Contact the Douglas County Park Division for more info on this county park.
North Union Lake was designated as an infested water in 2011 after discovery of zebra mussels in upstream lakes. Recreational users should take necessary precautions to prevent further spread of invasive species. Drain all water and remove all aquatic vegetation from your boat and trailer when leaving any body of water. Updated information on invasive species infestations can be found on the MN DNR website.
Narrative text from the Minnesota DNR lake survey.
Recent reports
North Union Lake fishing reports
Recent reports on North Union 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.
DNR bathymetry
North Union Lake depth map
Within 30 miles
Nearby lakes
- Lake Stony · 87 ac · 0.4 mi
- Lake Brophy · 297 ac · 0.7 mi
- Lottie Lake · 46 ac · 0.9 mi
- Lake Cowdrey · 243 ac · 1.1 mi
- Lake Louise · 215 ac · 1.2 mi
- Lake Darling · 1,050 ac · 1.6 mi
- Lake Mina · 411 ac · 2.6 mi
- Lake Henry · 152 ac · 2.7 mi
Quick answers
Frequently asked questions
How deep is North Union Lake?
North Union Lake reaches 42 ft at its deepest point with a mean depth of 5 ft; about 75% of the lake is littoral (15 ft or shallower).
How big is North Union Lake?
North Union Lake covers 118 acres with about 4.1 miles of shoreline.
How clear is the water in North Union Lake?
DNR Secchi readings on North Union Lake average 15 ft of visibility, clear water for a Minnesota lake.
What fish are in North Union Lake?
Minnesota DNR surveys (most recently 2018) record walleye, largemouth bass, northern pike, bluegill, crappie, yellow perch, rock bass.
Is North Union Lake stocked?
No stocking is on record for North Union Lake in the DNR's stocking database.
How big do walleye get in North Union 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 1997.
When was North Union Lake last surveyed?
The Minnesota DNR last surveyed North Union Lake in 2018, the most recent of 7 surveys on record. A survey that old is a starting point, not a current reading.
Page updated .
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