Be sure to take a look at the concourse map either online or in the inflight magazine. PHX labels their concourses weirdly, at least from the perspective of connecting passengers -- though US only uses "A" and "B", those are really 4 separate concourses. From left to right:
A15-30
A1-14
B1-14
B15-28
So A1 to B1 isn't too far, but A30 to B14 is 2 concourses away plus the distance. I understand the letters match the security checkpoints, but once inside they really don't make sense like that.
60-68 minutes should be okay, but beware if you have what happened to me on the Saturday of Memorial Day weekend: 50 minute connection; we arrived 5 minutes early...but waited 30 minutes for a gate. Had to run from something like A23 to B11, 2 concourses away, and the terminal was packed full of people that morning (didn't see any carts). Only made it before boarding closed because I gently shoved a few rude bozos on the plane back into their row who didn't think we were serious about people having tight connections and they could take all the time in the world to pull their carryons out. Hint: there should be little gap between people exiting in the aisle as you grab your stuff and go. If the last person is 30 feet down and you're still fumbling with your bag, you're holding up others and need to step in and wait until you have room to do what you need.
But normally PHX is fairly easy for connections.