AMC!

The Appalachian Mountain Club was founded in 1876 in order to help maintain and protect the Appalachian Mountains in the North East US.  They are actually the US’s oldest nature conservancy group.  I have personally done work as a volunteer and have seen the work they do in order to keep the natural environment and educate in Leave-No-Trace hiking.  Those of us down in Virginia know of the Potomac Mountain Club, which is the southern version of the AMC.