| Heal the Bay | CA |
| Hawk Mountain Sanctuary | PA |
| Harris Center for Conservation Education | NH |
| HabitatYou | IA |
| Gulf Specimen Marine Lab | FL |
| Greenpeace USA | DC |
| Greenbelt Alliance | CA |
| Green-Rock Audubon Society | WI |
| Greater Yellowstone Coalition | MT |
| Greater Wyoming Valley Audubon Society | PA |
| Great South Bay Audubon Society | NY |
| Great Plains Restoration Council | TX |
| Great Old Broads for Wilderness | CO |
| Great Lakes United | NY |
| Great Lakes Indian Fish and Widllfie Comission | WI |
| Grand Canyon Wolf Recovery Project | AZ |
| Grand Canyon Wildlands Council | AZ |
| Grand Canyon Trust | AZ |
| Government Accountability Project | DC |
| Gotham Bat Conservancy | New York |
| Glen Canyon Institute | UT |
| Georgia Native Plant Society | GA |
| Georgia Highlands College | GA |
| Gaviota Coast Conservancy | CA |
| Gasparilla Island Conservation | FL |
