On our last trip to Sequoia/Kings Canyon (SEKI) we visited a few lakes that get a little more traffic than is usual in the backcountry. Every area deals with this in a different way, since that additional traffic has three major impacts on the wilderness experience.
1. The campsites themselves get really worn out. That's why you'll find areas that have been obviously well-used, but are no longer open to camping. We've seen this everywhere in the Sierra. It allows the sites to recover, and there are always other options that work.
2. For camping in areas where there are over-interested bears, there are occasionally food storage lockers (bear boxes) that gives hikers a place to store their food safe from ursine marauders. We always carry a bear canister these days, but we certainly understand why the authorities install these bear boxes in high traffic areas. They really do make safe food storage a lot easier, and that makes saving the bears a lot easier.
3. And then there are the toilet facilities. Too many backpackers can have a very ugly impact on a heavily used campsite area. So in a few places in the backcountry, you'll find a vault toilet. It's not exactly our idea of wilderness, but we understand the problem, and we don't have a better solution.
We were particularly taken with this toilet at Twin Lakes in SEKI. It was certainly not your traditional vault toilet, and M was quite sure she we never find it easy to use...but still.; nice effort. And a lovely view from the throne.