I worked in the field for many years in Colorado

Every county or metro area has what is called a Community Centered Board - for example Adams County's is North Metro Community Services, Jeffoco is Developmental Pathways etc... Definatly contact the board and they can discuss everything from IEP's and services to support groups and general information

The JFK center also does some good evaluations and has good supports for families
DDRC provides in home services for folks in the metro area as does Foothills Gateway...
North Metro link is
http://www.nmcommserv.com/ - they provide services for both adults and children
you can also visit the CACCB.org site for a full list of the CCB's in Colorado