About 1990 I was inspired by this song to read a book, and I wrote a review of that book for a gay sf apa I belonged to at the time. It contains (at least) two mistakes, which are flagged here:

Book recently read: _The Horse of the Americas_, by Robert
M. Denhardt (2nd ed., Univ. of Oklahoma Press, 1975). Read because in
November I bought a record, _The Heart of the Appaloosa_, by Fred
Small. (It was remaindered at the Glad Day Bookstore, so I guess he
must be gay. [WRONG! -- 2002] There is always _some_ connection.
Cute, too.) The title song, which I had heard on the radio some years
ago and liked because it had a tune & stuck to the facts, tells the
usual sickening story of our encroachment on some Indians in Idaho --
first the missionaries, then the squatters, then the army,
displacement, and death. It centered on the natives' horses, which
were adapted to hilly country.

This reminded me of some questions I had wondered about for many
years. One always thinks of Indians as having horses, and so they did
during most of the long agony of their intercourse with whites. But
horses were extinct in America at the time of Columbus -- recently
enough that it may have been men that killed them off, but long enough
before that none of the natives had heard of them. How did they get
horses -- mostly from the whites, or from each other, or from the
wild? What effect did horses have on the native cultures? Did they
spread from tribe to tribe by imitation, or by conquest? On what time
scale did they spread? Here, under the eyes of literate people,
[WRONG! -- 2002] occurred a process that was prehistoric in Eurasia,
and that is thought by some to have accompanied the spread of the
IndoEuropean languages. Well, did horses alter the linguistic map of
America?

This book, which I found in the Harvard catalog, barely touches on
these questions. It is mostly concerned with the Spaniards who
brought the first horses over. However, it is entertaining on that
subject, and it has some useful chronology for my purposes, as well as
some pertinent references that I will look up. It also has some
pictures of Appaloosas; it seems there is an organization of people
who fancy them. Whether any humans of that tribe (Palouses) belong,
or even exist, is not mentioned.