I wouldn't cut anything at the entrance to a trail - but after I'm a mile or so in if I come across fallen trees I'm taking them out. If they're suspended I lash the lighter side down to something sturdy and put the Husqvarna to work. I'm sure different areas have different rules, but I've actually had a state park in NC list a chainsaw as part of recommended gear when going on the trails. I've actually been about 6 miles into a trail and come across like 5 pines that had fallen across the trail in a bunch as they fell together down a gorge. I put down some safety straps, checked what was down the slope below where the rest of the trees were going to fall and got to work. I had 2 of them cut and looked around. I never even heard the Forestry Service UTV pull up. I never even heard another chain saw start up until I finally let mine idle back down. The guy just gave me a grin, a nod, and then helped me clear the rest. When we were done he shook my hand and thanked me for the help. It was kind of surreal. He said most of the trails are kept to be maintained for fire control or as slide-stops in the wooded gorges we have around here. If you only winch the trees to the sides of the trail it'll effect the flow of water down the hills. Somebody still has to come through to cut that stuff up into smaller sections and kick it on down off the ridge line. Different rules for different places though. South Carolina State Parks it is a huge no-no. North Carolina State Parks encourage it. Most of the National Forests in my general area are fine with it though. As long as you aren't dropping standing trees, cutting stuff on private property, or cutting stuff off trails that aren't marked or blazed - no problems.