Hot answers tagged leave-no-trace
This is country specific - but yours may have some automated way of reporting this. My own little homeland made me proud when they rolled out a smartphone app for hikers that allows to report any kind of environmental damage (along with GPS data and possibly pictures) directly to the authorities. They are usually pretty quick to investigate such things.
If it is a more polluted area, try the method suggested by WedaPashi (cleanup activity with friends), or take a look at Let's Do It - a worldwide trash-collecting/volunteering action; find your country and contact the local organization. This also puts the issue in an other light (and on the world map), and it might get bigger media attention too, spread the ...
Contact USFS via their website and let them know the location and description of the item. They have a 'Contact Us' link in the About the Agency drop-down menu.
If you cut it up, then many hikers could each take out a piece and eventually the job would be done. Just leave it better than you found it.
Only top voted, non community-wiki answers of a minimum length are eligible