Stay On the Trail
Concentrating travel on trails reduces the likelihood that multiple routes will develop and scar the landscape. It is better to have one well-designed route than many poorly chosen paths, so don't venture off-trail unless you absolutely must when yielding. Otherwise, going off-trail can damage or kill certain plant or animal species and can hurt the ecosystems that surround the trail.
Always walk single file in the middle of the trail, even when wet or muddy. Trail braiding-when hikers go around established trails (usually due to a puddle or other obstacle) and widen the trail-dislodges soil and can lead to sediment getting washed into our waters, degrading water quality and fish habitat. Overtime, off-trail boot prints can also badly erode switchbacks and destroy drainage diversions.