Welcome! to Cora Leland's Late Night Woozy Words!
Despite altitude sickness, then the flu, Rescuing Chrissie (Lakota 6) is up & running on Amazon. https://www.amazon.com/gp/product/B0BPCNZ9KP
Things you might enjoy searching are these long-tailed keywords: The Overland Trail (1820-1869); Northern Arapaho and Cheyenne (1600-1878); Green Valley Rendezvous. (People do write saying they like to study these things.)
And here's a good site for looking at ledger art. But do note that this isn't a museum but a commercial site. Click carefully if at all. Just read and look... that's what I do. https://prairieedge.com/native-american-ledger-art
Here's a ledger art drawing by the Oglala artist Black Road. The decorations on the horse would have specific meanings. For example, the horse that my heroine, Chrissie, wore were engagement decorations that the groom (Bear Wolf) gave to Chrissie. In the author's words, these decorations included blue and white leather braided into the pony's tail and designs hanging almost to the ground from Chrissie's saddle.
Black Road's highly decorated pony