Do you want to be able to judge how big a deer is that far away or just watch the deer? If you're looking at just watching deer/elk and their habits look for a Nikon 20-60x with an HD lense. Unbelievable clarity for the money. I don't think you're gonna be able to find anything that will let you judge how big a deer is for $500 that far away. 10 miles is a long way. So you're going to have to tell us what works for that far. You might want to borrow a Wilde rangefinder, then you could tell exactly how far away it is. I know for a fact that it will give you a good reading on a cellular tower from about 6 miles. Now, I just need some kind of gun to shoot that far
