| Guadalupe Blanco River TrustSeguin | Form 990 | $729,066FY2025 |
| International Palm Society IncAustin | Form 990 | $729,027FY2025 |
| Friends of the Colorado River Foundation IncAustin | Form 990 | $725,169FY2025 |
| Bayou City Waterkeeper IncHouston | Form 990 | $721,185FY2024 |
| Trinity Edwards Springs Protection AssociationWimberley | Form 990 | $703,802FY2025 |
| John Bunker Sands Wetland CenterDallas | Form 990 | $692,090FY2025 |
| Bcarbon IncHouston | Form 990 | $673,504FY2024 |
| Longview Arboretum and Nature CenterLongview | Form 990 | $670,705FY2024 |
| Rise and Shine Ministries IncorporatedRichardson | Form 990 | $648,747FY2024 |
| Environmental Fund for TexasAustin | Form 990 | $647,688FY2025 |
| Peckerwood Gardens Conservation Foundation IncHempstead | Form 990 | $614,837FY2024 |
| Shoal Creek ConservancyAustin | Form 990 | $607,812FY2025 |
| Greater Edwards Aquifer Alliance IncSan Antonio | Form 990 | $605,707FY2025 |
| National Network of Abortion FundsEl Paso | Form 990 | $599,680FY2026 |
| Central States Air Resource Agencies AssociationAustin | Form 990 | $585,413FY2025 |
| Texas Health and Environment Alliance IncHouston | Form 990 | $579,887FY2025 |
| Consumer Energy Education FoundationHouston | Form 990 | $577,690FY2025 |
| Friends of the Fredericksburg Nature CenterFredericksburg | Form 990 | $577,612FY2025 |
| Bobwhite BrigadeNew Braunfels | Form 990 | $564,543FY2024 |
| Texas Property Assessed Clean Energy AuthorityAustin | Form 990 | $546,519FY2024 |
| Tejas Roadrunners Non-Profit CorporationHuntsville | Form 990 | $529,766FY2025 |
| North American Process Technology Alliance NaptaDeer Park | Form 990 | $522,292FY2025 |
| Families in NatureAustin | Form 990 | $508,479FY2025 |
| Friends of Quinta MazatlanMcAllen | Form 990 | $498,593FY2024 |
| Solid Waste Association of North America IncGrapevine | Form 990 | $491,881FY2025 |
| Scenic Houston IncHouston | Form 990 | $489,666FY2025 |
| Texas Land Trust CouncilWimberley | Form 990 | $486,242FY2025 |
| Efbc Conference IncThe Woodlands | Form 990 | $483,900FY2025 |
| Frontera Land AllianceEl Paso | Form 990 | $457,719FY2025 |
| Keep Midland Beautiful IncMidland | Form 990 | $444,268FY2025 |
| Devils River ConservancyAustin | Form 990 | $440,938FY2024 |
| Blue Sky Maritime Coalition IncHouston | Form 990 | $440,840FY2025 |
| Climate Advocates Voces UnidasUniversal City | Form 990 | $437,100FY2025 |
| Lower Rio Grande Valley Nature CenterWeslaco | Form 990 | $425,949FY2025 |
| EartheroRichardson | Form 990 | $400,000FY2025 |
| South Texas Weather Modification AssociationPleasanton | Form 990 | $394,246FY2025 |
| Downtown Austin Development CorporationAustin | Form 990 | $392,207FY2025 |
| Galveston Island Nature Tourism CouncilGalveston | Form 990 | $390,390FY2025 |
| Thirsty Ground InternationalCorpus Christi | Form 990 | $383,443FY2024 |
| Will Erwin Headache Research FoundationHouston | Form 990 | $382,577FY2024 |
| Sam Houston Trails CoalitionWillis | Form 990 | $379,575FY2025 |
| Preservation of South West Texas WildlifeRocksprings | Form 990 | $378,331FY2024 |
| Downwinders at Risk Education FundDallas | Form 990 | $364,978FY2025 |
| Ecology Action of Texas IncAustin | Form 990 | $354,845FY2024 |
| The Texas Environmental Health AssociationGeorgetown | Form 990 | $350,561FY2025 |
| Marine Insurance Seminars IncWeatherford | Form 990 | $347,030FY2024 |
| Renewable Energy for Better Life FoundationPlano | Form 990 | $341,662FY2024 |
| Three Mountains OrganizationEl Paso | Form 990 | $340,672FY2024 |
| Crowes Nest Farm IncManor | Form 990 | $336,946FY2024 |
| Center for Environmental AccountabilityHurst | Form 990 | $331,885FY2025 |