| Business | Phone |
| Wmr Waste Minimization 5025 Jensen Dr B, Houston 77026 | (713) 676-1000 |
| Bayou Preservation Assn 3201 Allen Pkwy 200, Houston 77019 | (713) 529-6443 |
| Citizen's Environmental 3015 Richmond Ave 270, Houston 77098 | (713) 524-4232 |
| Citizens' League For Envrnmntl 5120 Woodway Dr 9004, Houston 77056 | (713) 524-3000 |
| Earth Foundation 5401 Mitchelldale St B4, Houston 77092 | (713) 686-9453 |
| Entertaining Ro-Les Inc 5300 N Braeswood Blvd # 363, Houston 77096 | (713) 667-5363 |
| Fluor Gss 8101 W Sam Houston Pkwy S, Houston 77072 | (713) 596-7500 |
| Memorial Park Conservancy Inc 1001 E Memorial Loop, Houston 77007 | (713) 863-8403 |
| Legacy Land Trust Po Box 980816, Houston 77098 | (713) 524-2100 |
| Houston Audubon Society 440 Wilchester Blvd, Houston 77079 | (713) 932-1392 |
| Houston Wilderness 4916 Main St 230, Houston 77002 | (713) 524-7330 |
| Katy Prairie Conservancy 3015 Richmond Ave, Houston 77098 | (713) 523-6135 |
| Mothers For Clean Air 3100 Richmond Ave 309, Houston 77098 | (713) 526-0110 |
| Narba 440 Wilchester Blvd, Houston 77079 | (713) 464-2473 |
| Natural Legacy Po Box 541125, Houston 77254 | (713) 520-5008 |
| Nature Conservancy 1800 Augusta Dr 240, Houston 77057 | (713) 524-6459 |
| Nature Heritage Society 2900 Holman St, Houston 77004 | (713) 738-8016 |
| Nature Heritage Society 4103 Brisbane St, Houston 77047 | (713) 738-8016 |
| Saving Animals Across Borders Po Box 130897, Houston 77219 | (713) 527-4490 |