Some may remember the story of Pete Absolon's death in 2007 as told in Outside Mag. http://www.outsideonline.com/outdoor-adventure/climbing/rock-climbing/Dropped.html?page=1
Just short of the summit of a Wind River climb, he was killed instantly by a rock thrown from the summit, when someone up top couldn't imagine anyone was below them.
We'll all agree that the cliffs have gotten incredibly, even mid week and throughout the year, leave it the ranger staff to decide and if necessary when and how to trundle anything. As preserve employees, they have the authority, as well as the manpower to close off a section of the crag as well as the carriage roads as needed to insure it's done safely.