I have hunted two early hunts, both in the Rawah wilderness. The hunt was limited to the wilderness area or above 10,000ft.

I started scouting for both hunts in late July and right through early August. The deer were there but many high basins that looked like ideal habitat were just empty. so just going in cold w/o scouting is going to be a crap shoot. A lot of great country that just does not hold deer. Because it was pretty warm the deer would be out for just a short while and then usually bed. Ditto on the evening. On bright days they were usually not out until it was pretty late. Most of the areas required me to stay overnite due to the distance walking in. If I did walk in there would be a long walk out in the dark.

Thunderstorms are almost a given every afternoon with hail, lightning, and heavy winds and downpours. Choose your camping spot carefully.
Your spotting scope and binoc's are your friends. I usually glassed from a high ridge where sometimes I could move just a little and glass 3 different basins without going into them and spooking deer.. The deer are usually not spooked and often in small bachelor groups of bucks. It is a beautiful time to be in the high country. I never saw another person on any of my hunts.
Once I located a buck I often stashed some supplies/freeze dried food etc. So I could stay a while during the hunt without a really heavy pack in.

I took two nice deer that unfortunately burned up in the high park fire with my house two years ago. Not monsters but mature high country bucks.
Sept is a great time to be in the high country.

I have 4 preference points so with any luck I will be up there this year.

Have fun!

Lefty C