I would be interested in helping out with similar programs in Colorado. How do I find out about such organizations?
try nahra.org or Special Olympics
These should get you started. nahra.org may be headquarted in CO? Someone at your local Special Olympics can probably be of help as well.
Try those first and then post back if you haven’t found a group to help.
Like HiddenAcres recommended, I second checking www.narha.org for listings. Their website is a mess…they make you work to find things. But look for the listing of centers. I used to have the whole database plus more for a site I maintained for a while and I seem to remember there being several centers in CO 
