Nope

The very early clip of a jockey riding a horse, which Emerald claims features her and OJ's ancestor, is a real 1878 animated series of photographs, one of the first moving images ever, which has come to be called Sallie Gardner at a Gallop (1878). Sallie Gardner is the name of the horse; the two jockeys were listed as being named "C. Marvin" and "G. Domm." Neither of their identities are known, though they very well could have been black as Emerald claims. In those days many jockeys were black, such as thirteen of the fifteen jockeys racing at the first Kentucky Derby in 1875.

After the horse Clover is found wandering out in the field, the character O.J. begins to escort the horse back to its home. But once they start walking, the horse's mane changes colors between black and white (indicating two different horses were used). This happens about 45 to 46 minutes into the film.

At the very end of the credits, a cartoony image/advertisement appears: "Come ride through Jupiter's Claim, as seen in Nope, at Universal Studios Hollywood, only on the World-Famous Studio Tour."