One of Blacktails key to surviving is how sneaky and tricky they are. I have had bucks let me walk within yards of them. Whenever you are around any does, regardless of sign there could be a buck hanging around. Don't let yourself get to negative about not running into any decent bucks, that's how a lot of Blacktail hunting works out. Just stick with it and hunt hard and scout whenever you can, it will happen.
I have a theory an big bucks: I think they come out of wise old does. I have watched many times when younger does come in with fawns the fawns lead the way in bounding and frolicking. But a mature old doe so many times has her fawns following and she is sneaky and hyper-alert, just like a wise old buck AND WILL BUST YOU if you are not careful. Ears come forward towards you and you have been found out followed by a snort and/or stomp and the fawns skedaddle out of there and she whirls around after them.
That kind of goes with the old "ditch the head gear at the tree line" theory. We used to wonder how a herd of elk could absolutely dissapear. I think they are tunnelers.
I was in dog hair 4" caliber doug fir once, so thick I was no my knees going under the low branches to move forward, and my buddy spooked a herd of elk that ran past me within four feet and that herd included a big bull that damn near ran me over and not one elk was slowing down. Now, here is the hell of it... they didn't break off branches and that bull really had a wide rack on him.
Go figure