On the ground.
Seriously though, like someone mentioned, you'll get varied responses, but I can tell you for a fact that they do bed in clearcuts, you just have to find them. Most of the time they will be hidden, but once a year, you only have to find ONE that made a mistake. I've spotted blacktail by seeing only antler tines, a tail flicker, hind legs, they stand up at the same time I just happen to be glassing that area, they're with a younger buck who gives there position away, etc., etc. They make mistakes, you just have to be prepared when they do. I will say though, if it's a small clearcut, they will likely leave it to bed. It's the larger clearcuts that you will find them bedding in.
My 3 nicest blacktails have been killed at 1030am, 130pm and 2pm. All from glassing, spotting and stalking...in open country. So as others take mid-day naps, I'm still lookin' through my binocs.
This buck I got opening day this year at a little after 2pm. He was with a smaller buck that had stood up and fed into an opening some 1000 yards away. The little buck was in view for a good 10 minutes. This buck fed out after the little buck was out for a couple minutes and was across the open face in a matter of a minute. My brother in law and I stalked to within 200 yards, one ridge away, and took them both. Most guys don't glass all day...I do. I've learned my lesson time and time again!