Not sure if you have gotten a response.
The RMBO runs several banding stations in Colorado, they welcome visitors, but I am not sure of their dates, etc. I would recommend using the contact us link at the site above and they could probably provide more details. I am not a bander myself but have visited their Barr Lake site when the nets have been up and have enjoyed it. They encourage visitors, so it may just be a matter of timing.
you may also want to check the YMCA of the Rockies in Estes Park if your trip includes a trip to Rocky Mountain National Park. There are some banding sessions there as well.