| Missouri Botanical GardenEIN 43-0666759 | Environment | MO | $45,210,838Large | 87.76 |
| Mohonk PreserveEIN 14-1609484 | Environment | NY | $4,259,553Mid-sized | 81.21 |
| Montana Environmental Information CenterEIN 23-7337100 | Environment | MT | $527,862Small | 74.50 |
| Montana Wilderness AssociationEIN 51-0198932 | Environment | MT | $2,264,339Small | 96.25 |
| Mountains to Sound Greenway TrustEIN 91-1531234 | Environment | WA | $3,230,631Small | 96.46 |
| Naples Botanical GardenEIN 65-0511429 | Environment | FL | $8,405,351Mid-sized | 87.78 |
| National Audubon SocietyEIN 13-1624102 | Environment | NY | $104,107,085Large | 92.44 |
| National Environmental Education FoundationEIN 54-1557043 | Environment | DC | $3,621,403Mid-sized | 90.40 |
| National Forest FoundationEIN 52-1786332 | Environment | MT | $13,645,766Large | 93.66 |
| National Park FoundationEIN 52-1086761 | Environment | DC | $70,306,163Large | 91.50 |
| National Parks Conservation AssociationEIN 53-0225165 | Environment | DC | $31,688,823Large | 82.54 |
| National Tropical Botanical GardenEIN 52-6057064 | Environment | HI | $11,377,135Mid-sized | 92.74 |
| Native Seeds/SEARCHEIN 94-2899356 | Environment | AZ | $1,068,375Small | 78.07 |
| Natural Resources Defense CouncilEIN 13-2654926 | Environment | NY | $128,772,908Large | 93.49 |
| Nature and Culture InternationalEIN 33-0773524 | Environment | CA | $6,361,508Mid-sized | 93.91 |
| NatureServeEIN 52-1884438 | Environment | VA | $8,421,554Mid-sized | 84.93 |
| NC WARNEIN 56-1734433 | Environment | NC | $1,625,630Small | 75.89 |
| New Buildings InstituteEIN 68-0401509 | Environment | OR | $2,723,011Small | 89.68 |
| New England Forestry FoundationEIN 04-2024022 | Environment | MA | $2,723,042Small | 89.97 |
| New England Wild Flower SocietyEIN 04-2104768 | Environment | MA | $2,639,084Small | 89.30 |
| New Hampshire AudubonEIN 02-6005322 | Environment | NH | $2,319,775Small | 84.53 |
| New Jersey Audubon SocietyEIN 22-1539642 | Environment | NJ | $6,683,422Mid-sized | 94.64 |
| New Mexico Wilderness AllianceEIN 85-0457916 | Environment | NM | $1,183,856Small | 93.26 |
| New York Restoration ProjectEIN 13-3959056 | Environment | NY | $7,143,770Mid-sized | 80.87 |
| New York-New Jersey Trail ConferenceEIN 22-6042838 | Environment | NJ | $3,106,977Small | 99.71 |
| Norfolk Botanical GardenEIN 54-0788933 | Environment | VA | $5,367,710Mid-sized | 85.06 |
| North Carolina Botanical Garden Foundation, Inc.EIN 56-6076622 | Environment | NC | $1,521,702Small | 86.84 |
| North Carolina Coastal FederationEIN 58-1494098 | Environment | NC | $4,990,549Mid-sized | 97.68 |
| North Carolina Sustainable Energy AssociationEIN 58-1342588 | Environment | NC | $2,583,714Small | 89.27 |
| North Cascades InstituteEIN 91-1327775 | Environment | WA | $3,940,440Mid-sized | 95.46 |
| North Lakeland Discovery CenterEIN 39-1852858 | Environment | WI | $872,690Small | 82.53 |
| Northeast Sustainable Energy AssociationEIN 23-7437161 | Environment | MA | $1,399,599Small | 74.96 |
| Northern Plains Resource CouncilEIN 81-0367205 | Environment | MT | $1,377,941Small | 94.34 |
| Occidental Arts and Ecology CenterEIN 68-0359676 | Environment | CA | $1,944,634Small | 77.79 |
| Ocean ConservancyEIN 23-7245152 | Environment | DC | $23,984,534Large | 91.97 |
| Ocean Research & Conservation AssociationEIN 20-0901011 | Environment | FL | $1,613,797Small | 72.08 |
| OceanaEIN 51-0401308 | Environment | DC | $37,880,581Large | 94.11 |
| Ohio Environmental CouncilEIN 31-0805578 | Environment | OH | $2,085,734Small | 83.94 |
| Olbrich Botanical SocietyEIN 39-1357247 | Environment | WI | $2,874,467Small | 88.26 |
| Orange County CoastkeeperEIN 33-0847892 | Environment | CA | $1,772,988Small | 94.74 |
| Oregon Natural Desert AssociationEIN 94-3098621 | Environment | OR | $1,631,248Small | 94.83 |
| Organic Consumers AssociationEIN 41-1908341 | Environment | MN | $3,495,920Small | 87.44 |
| Outdoor Discovery Center Macatawa GreenwayEIN 38-2461102 | Environment | MI | $2,992,451Small | 88.77 |
| Pacific Crest Trail AssociationEIN 33-0051202 | Environment | CA | $3,359,863Small | 81.60 |
| Pacific EnvironmentEIN 94-2628924 | Environment | CA | $1,330,701Small | 86.58 |
| Park PrideEIN 58-1883895 | Environment | GA | $2,703,793Small | 93.91 |
| PATH FoundationEIN 58-1949696 | Environment | GA | $12,274,297Mid-sized | 96.23 |
| PennFutureEIN 31-1607866 | Environment | PA | $3,214,540Small | 90.24 |
| Pennsylvania Environmental CouncilEIN 23-7286159 | Environment | PA | $3,284,015Small | 89.71 |
| Phipps Conservatory and Botanical GardensEIN 25-1492587 | Environment | PA | $12,253,992Mid-sized | 92.53 |
| Piedmont Park ConservancyEIN 58-1551369 | Environment | GA | $3,079,715Small | 83.89 |
| Pinchot Institute for ConservationEIN 52-1935342 | Environment | DC | $1,567,804Small | 77.83 |
| Pinelands Preservation AllianceEIN 52-1641512 | Environment | NJ | $1,787,425Small | 91.11 |
| Pittsburgh Botanic GardenEIN 25-1648405 | Environment | PA | $1,549,227Small | 81.44 |
| Pittsburgh Parks ConservancyEIN 23-2882145 | Environment | PA | $13,182,731Mid-sized | 90.94 |
| Planet AidEIN 04-3348171 | Environment | MD | $40,116,928Large | 79.87 |
| Planting Fields FoundationEIN 11-1770097 | Environment | NY | $2,404,069Small | 87.56 |
| Project for Public SpacesEIN 13-2808114 | Environment | NY | $4,480,337Mid-sized | 83.89 |
| Property and Environment Research CenterEIN 81-0393444 | Environment | MT | $2,268,821Small | 90.88 |
| Prospect Park AllianceEIN 11-2843763 | Environment | NY | $9,890,402Mid-sized | 83.78 |