Folks running along trails has become increasingly popular, and its easy to see why. 1) No need to worry about cars, and 2) the scenery is constantly changing. Throw in the mix that some terrain can be as technically challenging as mountain bike tracks, and you have a sport that adventurous folks want to try.

Ultimately, another question arises, and this the impact all of these new runners are having on the environment. The American Trail Running Association (ATRA) has established guidelines to guide folks on how to enjoy their trail runs while minimizing the impact on the land.

Highlights are below. Details can be found here: http://runningtimes.com/Article.aspx?ArticleID=14695

Stay on the Trail
It's easy and sometimes an adventurous notion to shortcut a trail, but it's not good for the trails. ATRA encourages trail runners to stay on well-marked trails that already exist rather than blazing new routes or cutting switchbacks.

Animals
If you run with a dog (or a burro or a llama, for that matter), you've got to keep it under control and clean up after it.

Other Trail Users
We're not the only ones out on the trails. There are hikers and mountain bikers and equestrians all moving at a different pace. ATRA suggests runners be aware of other trail users and be ready to yield, even if you have a posted right of way.

Environmental Concerns
ATRA strongly encourages runners to "pack out at least as much as you pack in." Gel wrappers, with their little torn-off tops, and old water bottles don't have a place on the trail.

Safety
ATRA advises runners to know the area where they plan to run and to let at least one other person know where they are heading and when they expect to return.