That photo is a little dated, but yes Denver isn't exactly a skyscraper mecca. There is a law preserving sight lines to the mountains from the Capitol building, but it doesn't really hinder development as the CBD isn't between the mountains and the building.

I think Denver is a good model for OKC to follow. In the 60s the Skyline Renewal Authority cleared 27 city blocks in the urban core, destroying hundreds of lowrise structures, some historically significant, so downtown has had to rebuild its character slowly and organically. While the revitalization of downtown has been ongoing over the last 20 years, momentum has really picked up over the last 5 years. There are tons of low-to-mid rise residential structures being built that are bringing bodies downtown, which create great vibrancy. This has had a far larger impact on downtown than adding a skyscraper or two that alter the skyline. Though I would certainly kill to have a Devon Tower in Denver.