| Society for the Protection of Insects | CA |
| South Carolina Wildlife Federation | SC |
| South Shore Audubon Society | NY |
| Southern Environmental Center | AL |
| Southern Maryland Audubon Society | MD |
| Southern Resident Killer Whale Chinook Salmon Initiative | WA |
| Southern Utah Wilderness Alliance | UT |
| Southwestern Wisconsin Area Progressives (SWWAP) | WI |
| Species Unite | NY |
| Strong Foundation for Environmental Ethics | CA |
| Tahoma Audubon | WA |
| Tennessee Citizens for Wilderness Planning | TN |
| Texas Conservation Alliance | TX |
| The Activism Center at Wetlands Preserve | NY |
| The Caterpillar Lab | NH |
| The Conservation Agency | RI |
| The Conservation Angler | OR |
| The Earth Island Institute | CA |
| The Endangered Species Conservation Site | CA |
| The Fund for Wild Nature | CA |
| The Lands Council | WA |
| The Otter Project | CA |
| The Union for Reform Judaism | NY |
| The Urban Wildlands Group | CA |
| The Wildlife Society | MD |