If the item is small enough to move, but to large to easily carry out. Orginize the junk so that it is stacked as inoffensively as practical but remains easily accessible. Don't hide it or drop it into a ravine, you want to make it easier to remove not harder.

Contact the landowner or manager. This might be a park ranger, corporation or private land owner. Presumably, someone built and maintains the trail, after getting permission from the landowner or manager. This should put you in contact with the team who maintains the trail, you can inform them of the issue and schedule a time to work with them in the removal.

Alternately for objects that can be moved, but are to difficult to extract in a single event, move them closer to the entrance/exit. If you move it part way, and the next person moves it part way, it should find its way out fairly quickly.

If the item is small enough to move, but too large to easily carry out. Organize the junk so that it is stacked as inoffensively as practical, but remains easily accessible. Don't hide it or drop it into a ravine, you want to make it easier to remove not harder.

Contact the landowner or manager. This might be a park ranger, corporation or private land owner. Presumably, someone built and maintains the trail, after getting permission from the landowner or manager. This should put you in contact with the team who maintains the trail, you can inform them of the issue and schedule a time to work with them in the removal.

Alternatively, for objects that can be moved, but are too difficult to extract in a single event, move them closer to the entrance/exit. If you move it partway, and the next person moves it part way, it should find its way out fairly quickly.