In the United States, the wilderness act of 1964 established the management of people and natural resources within in designated wilderness to conform to a particular character. Ever since then men and women have worked tirelessly in order to preserve this character. Absolutely no structures, mechanized or motorized equipment is permitted. When campers spend hours on wood or stone camp furniture wilderness rangers dismantle it. Our ethic is so pure that we dismantle rock cariegns marking the trail. This is in strong contrast to the majority of trails on the east coast which use color blazes to mark the path.
I recall a time in which I strapped on no fewer than four metal grills to my exterior frame pack in order to remove them from the wilderness. Hundreds of hours are spent every year in Sierra National Forest alone in order to sift through the burnt remnants of campfire rings to remove the trash, dismantle the campfire ring and naturalize the area. By the end of a tour (anywhere from 5-7 nights) a large trash bag is often filled with the refuse left behind by recreational users.
The majority of backpackers don't have a wilderness ethic, and for that reason education is a huge component of the wilderness ranger's job. Hazards are not managed on the users behalf in the wilderness. The user is responsible to be prepared and observant. If a snag is hanging precariously over a popular camp site, it is not up to anyone but the user to realize that. The wilderness is by definition full of natural hazards. It is not planned to accommodate human safety and comfort. It is for this reason that we feel so alive in the wilderness. In the wilderness it is your right not to be protected nor guided.
American wilderness is not managed perfectly or consistently. While hunting is permitted wilderness areas within national forests, it is not permitted in national parks. Furthermore the National Parks are far too quick to ask for congressional approval to use chainsaws to clear trails within park boundaries. In comparison, Sierra National Forest had gone over 30 years without a chain saw being used within it's wilderness areas. Despite this, no campground is ever predetermined for you and you are able to camp upon which ever rock shelf, duff, dirt or snow that picks your interest.