You've heard the saying before. It deserves repeating everytime.
Taking care of the backcountry is a responsibility, not an option. What follows are a few tips you can follow to reduce the impact you have during your hiking/backpacking trip. For more details on low-impact hiking, visit the Leave No Trace web site.
1) Pack out what you pack in - a few gallon sized Zip-loc bags does the trick.
2) Leave the trail cleaner than you found it - you can make a big difference for the next hiker by picking up someone elses trash.
3) Don't build a fire unless you really have to. Fires scar the land. If fire rings are provided, use them!!!
4) Campsites and close proximities to rivers, streams etc. do not a good combination make. Run-off from soap, or worse yet, contamination from human wastes can cause a wide range of problems.
5) Keep the noise level down - it keeps the hike enjoyable for others and increases your chance of viewing wildlife.
6) Stay on the trail! For your safety and the health of oftentimes very fragile vegetation.
7) Learn how to dispose of human waste properly - besides being an offending site for someone else, there are some real health hazards that can crop up.
8) Pitch your tent in designated camping areas only.
9) Read Will Harmon's "Wild Country Companion" which is 196 pages of ethics which are not hard to follow but can really sharpen your outdoor etiquette.
10) Preach what you practice, so that others can learn good habits from you and together we can keep our outdoors beautiful!!!!