What Chuck said is vital: Check with the people who are in charge before cutting down any trees!
I agree (although sometimes I'm the one in charge :D). I was specifically thinking of out at blackhawk when I was riding last week and there's a bunch of branches that hang over right in front of the take off for a jump. Not such a good situation!
It took 4 sessions but the gully area is cut back, trimmed, and I also opened up a bridge over a gap in this picture if you know where it is.
That mess was a good example of why the FSTA training was important. it was all from a live and dead tree down and two widow makers.
The jump is open again.