I hunted 42/421 all of first season anywhere from 8.5k-10.5k feet. We were looking for elk (didn't see a single one), so we spent most of our time at the higher elevation. That being said, we did see a few deer each day with the majority of them around 9k. Saw one decent 4x4, but the rest were either fork horns or does. It was really hot (75 degrees) and no weather to speak of. There was much more deer sign than elk sign, not sure why there weren't any elk around or where they were. I can only speak to the area I hunted, but there weren't a ton of roads around (which was intentional) and put around 60 miles on the boots.
Good luck, let us know how you do!