I found these on a gravel/dirt road in the Black Hills National Forest, not very far from a main highway and only a couple of miles from Mt Rushmore. Since the weather is getting nicer, more people are getting out and enjoying the outdoors. The biggest industry of this area is tourism. All it would take is one tree hugger to see this dump site and it would be all over the news.
With all the snow we had over the winter, it was impossible to tell when these animals were killed. But by comparing the carcasses it appears that some were killed fairly recently, and it's been awhile since the season was in.
No one would want to see this in their yard. So why is it different since it's in the National Forest? Your yard belongs to you but the NF belongs to everyone. What if you lived across the road from this dump? I doubt anyone would say that it was ok since the carcasses will rot and return to the earth, sooner or later.