Robert, are those forest clearings man made?...I can't imagine any other way. Who would have cleared land on federal public land?, were they inholdings under some type of lease conditions that expired some time ago?. By the size of the manzanitas it would have been about 10 years ago?
The amount of garbage in protected areas is a world wide problem! We tried to provide garbage bags in the entrance gates asking to leave their garbage when they exited from the protected area. It did work partially since a fair amount of visitors gladly picked up the ruling, however not everyone...once a year the local hikers assoociation still has a day of mountain cleaning with school children..the amount of bags of garbage is amazing!