It's a real shame you didn't post this a couple of years ago as Grahame, formerly of these parts, for many years worked as a ride leader/guide for bikes rides in Colorado during the summers months, and for all I know he still does.
Unfortunately he longer rides with Addiscombe and it appears from his profile that he hasn't posted on here for almost 2 years. Shame as Grahame is one of the most helpful and knowledgeable cyclist I have ever met
Sorry none of this information is of the slightest use to you unless Grahame suddenly reappears between now and next May, but I thought I would rather unhelpfully point out that until recently Addiscombe had among its members a professional guide for bike rides in the Grand Canyon