| Whitefish Lake Conservation Organization IncGordon | Form 990-EZ | $91,626FY2025 |
| Friends of Horicon International Education Center IncHoricon | Form 990-EZ | $87,303FY2025 |
| Friends of Governor Dodge State ParkDodgeville | Form 990-EZ | $87,023FY2024 |
| Big Sissabagama Lake Shoreowners Association IncorporatedStone Lake | Form 990-EZ | $84,755FY2025 |
| Tomorrow River Valley Conservation Club IncAmherst | Form 990-EZ | $84,488FY2025 |
| Beaver Dam Lake Improvement Association IncBeaver Dam | Form 990-EZ | $83,311FY2025 |
| River Country Resource Conservation and Development RC & D Council IncEau Claire | Form 990-EZ | $82,968FY2025 |
| Friends of the ArboretumMadison | Form 990-EZ | $82,297FY2025 |
| Regeneration Equity and Justice IncAshland | Form 990-EZ | $81,541FY2025 |
| Maiden Lakes Association IncLakewood | Form 990-EZ | $81,074FY2024 |
| Lake Metonga Association IncCrandon | Form 990-EZ | $78,327FY2025 |
| Fox Lake Preservation Organization IncFox Lake | Form 990-EZ | $76,407FY2026 |
| Iron River Pike Chain of Lakes Association IncIron River | Form 990-EZ | $74,465FY2025 |
| Green-Rock Audubon Society IncJanesville | Form 990 | $72,486FY2025 |
| Friends of Governor Nelson State ParkWaunakee | Form 990-EZ | $71,958FY2025 |
| Lafayette Ag Stewardship AllianceSouth Wayne | Form 990-EZ | $71,795FY2024 |
| Star Prairie Land Preservation TR IncStar Prairie | Form 990 | $70,781FY2025 |
| Westfork Sportsman Club IncViroqua | Form 990-EZ | $70,544FY2024 |
| Pishtaka Wildlife Foundation IncBurlington | Form 990-EZ | $70,442FY2024 |
| North and South Twin Lakes Riparian Association IncPhelps | Form 990-EZ | $70,431FY2025 |
| Spread Eagle Chain of Lakes IncFlorence | Form 990-EZ | $69,917FY2025 |
| Green Tree Garden Club IncMequon | Form 990-EZ | $69,820FY2026 |
| Fox Cities Greenways IncMenasha | Form 990-EZ | $68,247FY2025 |
| Lake Poygans Sportsmans ClubLarsen | Form 990-EZ | $67,802FY2024 |
| Roots and Branches IncWest Bend | Form 990-EZ | $67,750FY2025 |
| Friends of Pike Lake IncHartford | Form 990-EZ | $67,744FY2025 |
| Wheeler Lake AssociationLakewood | Form 990-EZ | $64,818FY2025 |
| Friends of Beaver Lake IncHartland | Form 990-EZ | $62,979FY2025 |
| Silver Lake Preservation Association IncLaona | Form 990-EZ | $62,938FY2025 |
| Kettle Moraine Garden Club IncNashotah | Form 990-EZ | $62,792FY2025 |
| Friends of Lake Kegonsa Society IncStoughton | Form 990-EZ | $61,545FY2025 |
| Friends of the Evjue School Forest of Merrill IncMerrill | Form 990-EZ | $61,338FY2025 |
| International Association of Meteorology and Atmospheric SciencMadison | Form 990-EZ | $60,423FY2025 |
| Foxhead Regenerative Agriculture ProjectGreen Lake | Form 990-EZ | $60,045FY2024 |
| Teal Lost Land and Ghost Lakes Improvement Association IncHayward | Form 990-EZ | $59,192FY2026 |
| Apostle Islands Historic Preservation ConservancyBayfield | Form 990 | $58,851FY2025 |
| Deer Creek Sport & Conservation ClubVerona | Form 990-EZ | $58,383FY2026 |
| Southeast Wisconsin Land ConservancyOconomowoc | Form 990 | $58,008FY2025 |
| Platteville Community Arboretum IncPlatteville | Form 990-EZ | $58,003FY2025 |
| Forward Emdowment TRGreen Bay | Form 990 | $55,129FY2025 |
| Koenigs Conservation AssociationSheboygan Falls | Form 990-EZ | $53,221FY2025 |
| Watershed Program of Southeast Wisconsin IncRacine | Form 990-EZ | $52,594FY2025 |
| Sauk Prairie Conservation Alliance IncBaraboo | Form 990-EZ | $51,538FY2025 |
| Durand Sportsmans ClubDurand | Form 990-EZ | $50,153FY2026 |
| Art & Nature CenterWashington Island | Form 990-EZ | $49,260FY2025 |
| Whitetails Unlimited IncMarshfield | Form 990-N | No figure |
| Belmont Sportsmens Club IncBelmont | Form 990 | $46,509FY2025 |
| Cambria Conservation ClubRandolph | Form 990-EZ | $45,742FY2024 |
| Butte Des Morts Conservation Club IncButte Des Morts | Form 990 | $44,158FY2024 |
| Waukesha County Green Team IncWaukesha | Form 990-N | No figure |