Here are four more Union Pacific postcards that originally came in pairs. Since they have already been separated, we can only guess which ones originally came together.
Judging from color photos of Bryce Canyon, the colorist applied a little too much red and not enough orange to this postcard. However, the only contemporary photo I can find of the same rock formation looks pretty red as well.
It seems reasonable to assume that a postcard of Bryce would be paired with one of Zion. However, the inventory numbers on the back of the Rainier/Multnomah Falls postcards were similar to one another: 111212 and 111217. The inventory numbers on the Bryce and Zion cards are not: 88370 and 101126. That may not be relevant, however.
The photo of the Great White Throne is the only one of this group that has a photographer’s name: A. Wilkes. I can’t find any information about this photographer on the web other than that he took a number of other photos of Zion and Bryce parks that were used in postcards in the same era.
The above postcard of Mt. Moran was the left half of a pair, while the below postcard of Longs Peak trail was the right half. Did they once go together?