American Forests

The oldest national nonprofit conservation organization in the country, advocates for the protection and expansion of America’s forests.

American Grove

Committed to sustaining our green legacy by helping communities grow healthy trees.

Native Tree Society

A non-profit scientific organization dedicated to the study of trees and forests. Their Forums has a wealth of information about big trees and lots of incredible photographs, too.

Old-Growth Forest Network

Organized by Joan Maloof, OGFN's purpose is to build a network of old-growth (or future old-growth) forests across the U.S., where visitors will be able to experience native forests in their mature diversity and complexity.

Tree Foundation

Margaret ("CanopyMeg"), Executive Director
Pursues and promotes research, education, and exploration to advance the conservation of our planet's botanical resources and ecosystems dependent upon them.




Tree Climbers Coalition





Go Tree Climbing