Nice page - wondering about the intro portion where Front Range is said to be furthest east in CO - the Spanish Peaks are further east than Pikes, and Fishers Peak is four quadrangles east of the Spanish Peaks. The relief of the Front Range is not unique - the Sangre de Cristos also have this on the east side.
Traditionally the Front Range southern border is the Pikes Peak Massif. I agree that the "Greater Front Range" covers Spanish Peaks and Fishers Peak (also pointed out by Noel & Fielder in a book Colorado 1870-‐2000 Revisited: The History Behind the Images). I recently finished the Front Range Atlas, called "Eagle’s View of the Front Range" that covers those. You may download a pdf file of it from http://pikespeakphoto.com/aerials/front_range.html Note: it's a 53M file: 572 pages.
"Got tight last night on absinthe and did knife tricks. Great success shooting the knife into the piano. The woodworms are so bad and eat hell out of all furniture that you can always claim the woodworms did it."