Welcome from Boulder!
I purchased my pup from Rocky Mountain German Shepherds. They are located in Conifer. There are quite a few breeders out here so depending on what you are looking for (Working Line or Show line) I would recommend visiting a couple of clubs that are doing schutzhund if you are interested in doing that.
What breeder have you visited so far?
Bear GSD 10/16/11
Elsa GSD 12/23/03 - 11/10/11