Two antelope horns are lightly added to this simple drawing which may well have been a preparation study for a later painting. There are several other similar drawings from around this period in which the artist slowly adds more and more detail as she builds each overall composition. Her focus is entirely on these animal bones, and so she leaves out any detail from the rest of the paper, making this not so much a presentable artwork, but a highly focused study piece. It is the subtle and smooth surfaces delivered in Antelope Horns which makes this particular piece so memorable and it is believed to have been put up for auction in recent years, perhaps suggesting that previously it was within a private collection rather than owned by the artist's own estate - she left many of her drawings to this organisation which continues to protect and promote her achievements.
The artist travelled around rural parts of the US looking for animal bones and skulls to use for her work. She would produce both drawings and paintings from them, with some of the more famous interpretations including Rams Head Blue Morning Glory, Horse's Skull with Pink Rose and Pelvis with the Distance. She would really exhaust this genre over several years and paid it more attention than pretty much any other famous 20th century artist. The only other prominent use of skulls that one can remember would be as a symbolic touch within North European art many centuries ago where it could be added to still life arrangements to signify death or danger. O'Keeffe's use was far more positive and inventive, though she understood the need to practice prior to starting each painting, exploring as she went.
One of the great masters who was particularly adept in sketching was Spanish painter, Diego Velazquez. His drawings helped him to show off his potential from an early age, just as O'Keeffe would do many centuries later. The artist was encouraged by his father to master this art form prior to even thinking about the use of oil or tempera and this helped to provide him with a strong base as an artist that would then benefit everything that he went on to produce across his career. He remains known as one of the most famous Spanish artists of all time and came during a successful period for this nation which included a number of other highly notable contributors. Although working in a very different style, O'Keeffe must surely have benefited from studying the masters in her own early development.