I agree that a fence is the best deterrent. The funny part, for me, even a fence that is really not all that sturdy works, if the deer sense that there is really no place to land if they jump it. My fence at the top of the slope is held up by wishful thinking. I don't have the time or money to pay someone else to put in new posts, so I just kind of propped them up. The deer don't even bump into the fence, even those with large racks.
Someday, I might do a better job of fixing the fence, but as long as it stays up, the deer believe it is a barrier. Town deer are trained to believe that stuff.
Smiles,
Lyn