Hikers cutting across switchbacks can trample down vegetation which holds topsoil in place. As the loosened earth washes away, an ugly ditch will form. Travel single file on most trails. Leave some space between you and the Scout ahead of you. You can see where you are going, and you won't run into him if he suddenly stops.
Hikers coming up the trail have the right of way.
If you meet people on horseback, stop where you are. Horses and mules may be spooked by hikers. Step four or five paces downhill from the trail and stand quietly while the animals pass. Do not pick, cut, or abuse any plants or animals. Leave all gates the way you found them.