| Maryland State Game and Fish Protective Association IncPerry Hall | Form 990-EZ | $73,436FY2025 |
| Friends of Sligo CreekTakoma Park | Form 990-EZ | $71,290FY2025 |
| Center for Ecological Living and LearningDerwood | Form 990-EZ | $69,268FY2024 |
| Elyssa Kellerman Foundation CorporationBethesda | Form 990-EZ | $67,750FY2025 |
| Catonsville Rails to Trail IncCatonsville | Form 990-EZ | $65,943FY2025 |
| Inclusive Clean Energy for Those UnderservedBowie | Form 990-EZ | $65,535FY2025 |
| Environmental Engineering FNDT IncAnnapolis | Form 990-EZ | $62,605FY2025 |
| Assateague Island AllianceBerlin | Form 990-EZ | $60,935FY2025 |
| Community Food Forest Collective IncTakoma Park | Form 990-EZ | $59,327FY2025 |
| The Maryland Recycling Network IncColumbia | Form 990-EZ | $56,210FY2025 |
| Meade Natural Heritage Association IncSevern | Form 990-EZ | $52,905FY2026 |
| Green Spring Valley Garden Club IncBrooklandville | Form 990-EZ | $52,436FY2025 |
| Maryland City Communities Association IncLaurel | Form 990-EZ | $50,725FY2025 |
| Upcycled IncColumbia | Form 990-N | No figure |
| Go Green Oc IncOcean City | Form 990-N | No figure |
| Kent Conservation and Preservation AllianceChestertown | Form 990-N | No figure |
| Summerseat Farm IncMechanicsville | Form 990-EZ | $39,092FY2025 |
| Calvert Environmental Trust for Youth IncPrince Frederick | Form 990-N | No figure |
| The Garden Club of the Eastern Shore IncEaston | Form 990-N | No figure |
| Horticulture Society of Maryland IncLutherville-Timonium | Form 990-N | No figure |
| Western Garret County State Park Volunteers IncAccident | Form 990-EZ | $32,662FY2025 |
| Holly Springs Nature Conservancy and Wildlife Sanctuary IncHampstead | Form 990-N | No figure |
| Port Tobacco River Conservancy IncPort Tobacco | Form 990-N | No figure |
| Bay Paddle IncArnold | Form 990-N | No figure |
| Global Smart Grid FederationBaltimore | Form 990-N | No figure |
| Long Green Valley Conservancy IncBaldwin | Form 990-N | No figure |
| Maryland State Geographic Information Committee LtdCrownsville | Form 990-N | No figure |
| Minnies Island Community Conservancy CorpCabin John | Form 990-N | No figure |
| Crownsville Conservancy IncCrownsville | Form 990-N | No figure |
| Muddy Branch Alliance IncGaithersburg | Form 990-N | No figure |
| Chesapeake Heritage Conservancy IncElton | Form 990-N | No figure |
| Prince Georges Audubon Society IncorporatedBowie | Form 990-N | No figure |
| Earth Help Today IncBethesda | Form 990-N | No figure |
| Concerned Citizens for Proper Land Use IncAnnapolis | Form 990-N | No figure |
| Southern Calvert Land TR IncLusby | Form 990-N | No figure |
| Lake Linganore Conservation Society IncNew Market | Form 990-N | No figure |
| Central Maryland Heritage League IncMiddletown | Form 990-N | No figure |
| Magothy River Land Trust IncSeverna Park | Form 990-N | No figure |
| Mid-Maryland Land Trust Association IncFrederick | Form 990-N | No figure |
| Clean Islands International IncPasadena | Form 990-N | No figure |
| Mid-Atlantic Renewable Energy CoalitionSilver Spring | Form 990-N | No figure |
| Bay Hundred Foundation IncSaint Michaels | Form 990-N | No figure |
| Little Magothy River Association IncAnnapolis | Form 990-N | No figure |
| Conservation MontgomerySilver Spring | Form 990-N | No figure |
| Beaver Creek Watershed Association IncFunkstown | Form 990-N | No figure |
| Friends of Helen Avalynne Tawes Garden IncEdgewater | Form 990-N | No figure |
| Maryland Chapter of the American Chestnut Foundation IncTakoma Park | Form 990-N | No figure |
| Chesapeake Education Arts and Research SocietySandy Spring | Form 990-N | No figure |
| Center for Responsible Technology IncBethesda | Form 990-N | No figure |
| Equestrian Partners in Conservation IncBoyds | Form 990-N | No figure |