"The Access Fund is a national, non-profit organization dedicated to keeping climbing areas open and to conserving the climbing environment." (From the Access Fund website) The organization is based in and focused on the United States. It was founded in 1989 as an independant offshoot of the American Alpine Club.
Fundamentally, the organization acts to improve and maintain the right to access areas for rock climbing. The basic problem is that most people think of rock climbers are crazy, thus if you are a land manager one way to reduce your headaches is to ban climbing in the area you manage. Of course, if the land you manage has cliffs, then most of the people who fall off the cliffs will be drunks and fools, not rock climbers. The Access Fund spends a lot of its time dealing with these sort of problems.
The organization primarialy deals with these situations through education and organization of grass roots action. At times the organization has arranged land swaps or even participated in land purchases in order to put climbing resources under good management. The organization has also done a great deal of work with issues related to the nesting of endangered raptors and rock art.