People from other parts of the country have no concept of how deep blue the Western sky can be. Add high altitude and it's even more so. However, the real culpret is that in the '30s and '40s AA (and other Western landscape photographers) just overfiltered the H out of their images, possibly in reaction to the earlier work (for example, Carlton Watins) done in the same areas with colorblind film which showed completely washed out sky.
Early prints of AA's most famout print, "Moonrise" show only a moderately dark expanse of sky, whereas the later paints are black as the ace of spaces. Obviously his intrepretation veered toward the dramatic.
When I first saw it in the '50s I was blown away. Now the feeling is more often like "hurl" than "blown".