Apparently the Calizona Appaloosa Horse Club dressed as (their idea of) Nez Perce Indians to honor the Nez Perce history with Appaloosas. A Facebook video shows a 15-second snippet of their ride. Here are some photos taken from the video.
And an album of photos from an Old Spanish Days ride on August 7 of last year. Which may have been a precursor to the Rose Parade ride.
According to those who contacted the club, none of the riders were Native. Most dressed as stereotypical chiefs and maidens in "leathers and feathers," although a few women wore Nez Perce-style hats.
A behind-the-scenes photo makes it clearer that these people are dressing in wigs and makeup--i.e., redface. As someone wrote to the Tournament of Roses:
Finally, the Nez Perce denied they gave the horse club any sort of permission or approval:
Nez Perce Did Not Give Horse Club Blessing to Play Indian at Rose Parade, Tribe Says
Oops. For more on stereotypical parades, see Debating an "Arab" Parade Float and Columnist Defends Mummers Parade.