The state's coastal commission ruled Eastwood and other investors in the Pebble Beach Co. cannot remove the trees in the Del Monte Forest to make way for another golf course development, The Los Angeles Times reports.
The 8-4 decision Wednesday follows years of political maneuvering that even included a local ballot measure favoring the plan.
But in the end, commissioners sided with environmentalists who cautioned removing trees and filling in wetlands to make room for the project would irreparably harm the fragile coastal habitat.
"It amounts to wholesale destruction of the environment, (and) destroys the essence of the Monterrey pine forest," said commissioner Sara Wan of Malibu.
In addition to a golf course, plans for the development included a driving range, equestrian center, apartments, and hotels.
An attorney for the developers says they will consider their options.