As a very rough general rule if the trees in front of you are far enough away that if they fell toward you and would not hit the antenna then you will have a clear shot over the top. So, a 50' tree 50' away will likely not cause you any problems. However, that same tree 25' away could block the signal unless you are in the Southern US. In FL, the satellite would likely still be above that tree only 25' away. In the South, I have set a satellite antenna on the picnic table beside the coach and still picked up the satellite.