HERE is an article from the mid-1950s from Howard
Zahniser on wilderness preservation. In the late 1950s, Zahniser was the main
lobbyist on behalf of wilderness in Washington and is generally credited with
seeing the Wilderness Act passed (he drafted the bill, which passed in 1964, 4
months after his death.)
HERE is a link to the story on Utah
off-roading and Differing views on snowmobiles
in Yellowstone (also update
HERE).