Sky Above Clouds IV came in 1965 and was one of an impressive series by artist O'Keeffe who had become inspired by this theme after travelling around the world by plane.
Air travel was still in it's relative infancy as a commercial enterprise during the 1960s and 1970s, meaning the artist would have felt even more excitement when peering through her cabin window.
The artist covered the sky in different moods as again she would put the same objects under different conditions as she did with leaves and animal bones.
The particular artwork was more of a mural, large scale and the sort of project that she had wanted to do for quite some time. Some of the previous cloud works were on a smaller scale.