Any ideas what business resided here and why they built the roof the way they did?

it was the: Western Electric mountain northwestern regional headquarters (i just added a pic to the gallery that has it written on the old door.)

the sign out front says "BellCO" parking only as in Bell telephone.

as for the roof being the way it is i have no clue. several of the valleys are flooded causing a few leaks inside the building.

i also found this picture of an old add

Interesting, were the bought out by Qwest when that started in the late 90's?

Western Electric (Weco) produced the hardware for the Bell telephone system, which basically had a 90% monopoly on telephone service nationwide. Every phone connected to the Bell system was made by Weco, and you would pay the phone company a rental fee every month to use that phone. You were also forbidden to hook up any non-Weco telephone to the bell system. They also manufactured a lot of the central office switches and whatnot, which is what this ad is talking about. ESS basically brought in direct dial long distance, call forwarding, call waiting. ESS is still the backbone of modern telecommunications.

After the Bell breakup, Weco went with AT&T and Bellabs while the network itself was broken up into parts. They were around until the mid 90's when AT&T, Bellabs and Weco were all folded up into Lucent Technologies.

And now ya know!

This also was a shopping center that was called Fan Fair. I think it was kind of merchandise-mart style shops.