George,
If you spend any time in Denver, drop by Trouts fly shop. The guys there are very kind and willing to point you in the right direction.
If you can make it out to the Roaring Fork Valley, it’s worth the 3 hour drive.
Like Rick said, the Blue is a closer option. I would also highly recommend anything along the South Platte (Cheesman, Deckers, etc.) for great day trips near the front range.
I just moved to the east coast from Colorado and I truly miss all the great trout water out there. Make sure to bring some terrestrials (maybe even a few mouse patterns) for some evening action during that time of year.
Good Luck!