What are the largest conservation groups in the United States?
Below is a look at the biggest U.S.-based NGOs focused on nature conservation.
But first, a few caveats:
🌳 This list includes only US non-profit entities, so it doesn’t necessarily represent the full scope of an organization’s work. For example, WWF and Greenpeace have several entities registered outside the U.S., which are not included in this analysis. This data is based entirely on 990 filings.
🐘 Some organizations have multiple entities within the US. For example, Audubon has at least 6 entities that had budgets exceeding $5 million in 2023. The Sierra Club has separate 501(c)(3) and 501(c)(4) entities.
💰 The ranking is based on annual expenses for the most recent fiscal year. Revenue can be “lumpy” due to the nature of nonprofit accounting. For example, the full value of a multi-year grant is typically booked in the first year, even though the money for subsequent years may not have arrived yet and may be conditional.
🐬 While some zoos have significant conservation projects, the only ones included on this list are the Wildlife Conservation Society (WCS), which runs the Bronx Zoo among other institutions, and the San Diego Zoo Wildlife Alliance.
🦎 The inclusion or exclusion of specific groups, insofar as whether they can be deemed conservation groups, is certainly open to debate.
Without further ado, here’s the list. All figures in millions of US dollars.
✅ US groups with large conservation programs
The Nature Conservancy (TNC) - 1120 (2023)
San Diego Zoo Wildlife Alliance - 391 (2023)
National Fish and Wildlife Foundation (NFWF) - 373 (2022)
Wildlife Conservation Society (WCS) - 374 (2023)
World Wildlife Fund (WWF) - 353 (2023)
Environmental Defense Fund (EDF) - 326 (2023)
The Conservation Fund - 305 (2022)
Ducks Unlimited - 291 (2023)
Conservation International (CI) - 247 (2023)
National Audubon Society - 159 (2023)
Sierra Club Foundation - 113 (2022)
National Wildlife Federation (NWF) - 109 (2022)
National Park Foundation - 101 (2022)
Resources Legacy Fund - 90 (2022)
Arbor Day Foundation - 86 (2023)
✅ Groups whose conservation work includes a substantial international component
Nature Conservancy (TNC) - 1120 (2023)
San Diego Zoo Wildlife Alliance - 391 (2023)
Wildlife Conservation Society (WCS) - 374 (2023)
World Wildlife Fund (WWF) - 353 (2023)
Environmental Defense Fund (EDF) - 326 (2023)
Conservation International (CI) - 247 (2023)
National Audubon Society - 159 (2023)
Rainforest Alliance - 69.9 (2022)
Wildlife Conservation Network (WCN) - 43.8 (2023)
BirdLife International - 38.7 (2022)
African Wildlife Foundation - 36.7 (2023)
Nia Tero - 33.8 (2022)
Rainforest Trust - 31.7 (2022)
Rare - 31 (2022)
African Parks Network - 29.3 (2022)
American Bird Conservancy - 25.6 (2022)
Other breakdowns coming soon: environmental groups (broader tha nature conservation), activist/advocacy NGOs, zoos & aquariums, environmental policy think tanks, etc.
