It always starts with Garden of the Gods and the two iconic figures: Eagle Beak, or Sphinx, on the right and Indian Head on the left.
"Dallas" is the only production where I've seen this cabin, which was built right in the middle of Garden of the Gods, somewhere behind Eagle Beak. I initially thought it may have been built on the relatively small patch of flat ground where a camera mount was also built, overlooking Iverson Gorge. (The track for that camera mount is still in place today.) But further research indicates that it was more likely a little to the west of that spot, probably tucked in behind Eagle Beak and Phantom. My guess is the cabin was built specifically for "Dallas" and was probably torn down soon afterward. Gary Cooper already had a track record of construction at Iverson, having been responsible for putting up Iverson Village for his 1945 movie "Along Came Jones." In that case the construction paid lasting dividends for Iverson, as the village was used in countless productions for the next couple of decades.
Lookouts were placed strategically on the rocks of Garden of the Gods, which served as an outlaws' hideout in "Dallas." In this shot the lookout is positioned near the base of Eagle Beak, or Sphinx.
Here's another lookout perched near Indian Head.
That's Cleft Rock on the left, just to the left of the clouds of gunsmoke. Cleft Rock is a relatively minor structure, but it has a distinctive shape and appears in a number of films. My attempts to find it at Iverson proved fruitless for months, but I finally located it thanks to this movie. It's in the North Cluster area, just above Garden of the Gods, near a group of condos. These days it's covered with ivy and barely distinguishable.
Here's a shot of Gary Cooper in Garden of the Gods for his starring role in "Dallas."