The best resource for finding a reputable dog breeder in Colorado is the American Kennel Club's website, AKC.org. The American Kennel Club provides a list of breeders who have been accepted into its Breeder of Merit program.
As of April 2015, visitors to the website can enter a state or name into a data bank and access names of reputable breeders who been accepted as members.
Breeder of Merit participants have demonstrated a dedication to the breeding of purebred dogs to a breed standard of temperament, ability and appearance. In order to be accepted into the program, a breeder must have at least five years of experience with the American Kennel Club, perform adequate health screenings, register their puppies with the AKC, and earn an AKC conformation, performance or companion event title for a minimum of four dogs they have bred.