A few options
I'm in Colorado Springs but work in Denver, and also want to try CX this season. Here are a few clinics and resources I've found lately in that quest:
The fine folks at Salvagetti Bike Shop/Happy Coffee have a fun oriented team starting and are putting on a clinic this Saturday!
Boulder Cycle Sport - Wed evening clinics, they encourage beginners and have a team.
There's an affordable 9-1pm clinic in the Springs on Sept 11th I'm definitely doing, PM for details.
There's also a very tempting clinic, Sept 11 and/or 12 in Fraser with a woman coach/clinic leader.
I'm sure there's more, but those are the most beginner-friendly and accessible (as in I found them without TOO much work). Let us know what you end up doing!
Sit bones = ~135 mm, saddles that work ~ 155cm/6.1 in wide
2003 da Vinci (custom road/all-rounder)/Terry Butterfly Ti
1994 Gary Fisher Nirvana (vintage MTB/commuter)/Terry Butterfly Chromoly
1991 Terry Symmetry (NOS frame/fork, project in progress)
1973 Raleigh Super Course (project in progress)