Cosmology has been the inspiration for artist's work for thousands of years. The earliest forms of art include suns and moons, often in a religious or spiritual symbolism.
Abstract art has also made use of the simplistic lines and shapes of the items, such as Joan Miro with his Red Sun painting. O'Keeffe continues this in some of her own work, such as with Ladder to the Moon as shown here.
This particular painting bears clear resemblance to a photograph of the artist and may have served as her study guide for it. The photograph was of her in Ghost Ranch and the surroundings match with what we see in this painting.
In Pueblo culture, which she is known to have studied at various times in her life, the ladder is used to symbolise the link between the native Pueblos and cosmic forces above. This group of people also inspired photographer Ansel Adams in some of his work, where he was drawn by the style of their housing.
The painting may represent the path of life in a similar way to The Tetons and the Snake River photograph by Ansel Adams.