Minnesota · DNR survey data
Willow Reservoir 4
Willow Reservoir 4 covers 36 acres in Olmsted County, running to 24 feet, last surveyed by the DNR in 2023. The Minnesota DNR has not published bathymetry for this lake, so there is no depth map here, just the survey record: what the nets held and how big it ran.
DNR survey data
Fish species
Largemouth bassGood numbers71.9per hr (electrofishing)10"Typical22"Biggest
Lengths measured · 66 fish
Recent · 2023Lengths measured · 66 fish
2023Lengths measured · 53 fish
2016Lengths measured · 51 fish
2002No recent survey rating.
BluegillPresent186.3per hr (electrofishing)6"Typical8"Biggest
Lengths measured · 171 fish
Recent · 2023Lengths measured · 171 fish
2023Lengths measured · 69 fish
2016Lengths measured · 250 fish
2002CrappiePresent104.6per hr (electrofishing)7"Typical9"Biggest
Lengths measured · 96 fish
Recent · 2023Lengths measured · 96 fish
2023Lengths measured · 1 fish
2016Only 1 fish measured that year — too few to read as a shape.
Lengths measured · 46 fish
2002Rates come from standard DNR survey gear (gill nets, trap nets, electrofishing), judged against statewide benchmarks for the same gear — which is why the same number of fish per net can read differently for two species. Where the standard gear can't count a species reliably, the page shows presence and size only. Typical is the middle fish of those measured. Open a row for the full length spread, survey by survey. You can read every number on this page without an app or an account.
Recent reports
Willow Reservoir 4 fishing reports
Recent reports on Willow Reservoir 4 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.
Within 30 miles
Nearby lakes
- Willow Reservoir 6A · 60 ac · 2.6 mi
- Silver Lake · 50 ac · 5.9 mi
- Cascade Ponds Lake · 72 ac · 6.4 mi
- Bear Creek Reservoir · 104 ac · 7 mi
- Silver Crk Reservoir SR-2 · 107 ac · 7.6 mi
- Foster-Arend Lake · 18 ac · 8.2 mi
- Kalmar Reservoir (KR-7) · 55 ac · 9.8 mi
- Zumbro Lake · 715 ac · 16.2 mi
Quick answers
Frequently asked questions
Is there a depth map for Willow Reservoir 4?
The Minnesota DNR has not published bathymetry for Willow Reservoir 4, so this page carries the survey record instead: species, catch rates and stocking history.
What fish are in Willow Reservoir 4?
The most recent DNR survey (2023) recorded largemouth bass, smallmouth bass, bluegill, crappie, yellow perch.
Is Willow Reservoir 4 stocked?
No stocking is on record for Willow Reservoir 4 in the DNR's stocking database.
When was Willow Reservoir 4 last surveyed?
The Minnesota DNR last surveyed Willow Reservoir 4 in 2023, the most recent of 4 surveys on record.
Survey numbers are the Minnesota DNR's. How this site reads them →
Page updated .