Visiting in September.....

I'm headed out for a conference in Denver next month. I'll be free for a couple of days to ride something not too far out of town on Thursday 9/9 and Sunday 9/12. Staying at the Hyatt Regency downtown, but will have a rental car. Looking for suggestions for a good shop to rent a bike and advice on some trails to hit up. On Thursday I have a meeting at 5PM, so probably won't have time for more than a 2-3 hour ride. On Sunday I have no other obligations (other than my wife will be pissed if I don't go somewhere where she can do some sightseeing, shopping, etc.). Or at least drop me off and come back in a few hours.

After checking online it looks like there are plenty of places to ride within an hour of downtown. I like riding technical xc, skinnies, stunts and drops up to 3-4 feet max. I ride 3-5 days a week and am in reasonably good shape for an old fart (47yo). Checking trails online I really liked stuff like the ridge ride on Dakota Ridge (singletrack with lots of rocks). Don't mind climbing, but I'm sure the elevation will be a factor. Don't have a problem riding the 3-5K elevations in Pisgah here in NC, but I'm sure anything over 7K will probably put a hurting on me. Particularly on the Thursday since I'm arriving Wednesday afternoon. And I'm used to climbing, crawling and pushing for 2-3 hours just to bomb downhill for 30 minutes.

Soooo...any advice? And if anybody is wanting to show me their favorite trails, that's even better.