One of the most exciting stories in American history is that of how the Indian got the horse and what this astonishing innovation did to change the culture of the red men of the Plains [see “How the Indian Got the Horse,” AMERICAN HERITAGE , February, 1964]. Indian horses were, of course, of Spanish descent, the first of them almost certainly stolen by members of the Pueblo tribe whom the conquistadors had enslaved. After the great Pueblo revolt of 1680 there suddenly were more than enough ex-Spanish horses to go around, and the long process of trading the animals from tribe to tribe across the Great Plains from Texas to Canada got under way. It can be documented that by the end of the first quarter of the eighteenth century horses were in use by Indians in what is now Montana. But though this is an oft-told tale, pictorial records of the great horsepower changeover are practically nonexistent. Lewis S. Brown, formerly with the American Museum of Natural History, is an artist-scientist who has spent years studying both Indians and horses. In a work tentatively called “Faster Travel in Montana” he has visualized the steps—fearful, excited, hesitant, daring, and, finally, triumphant—by which a band of Piegan Indians, the Magpies, gradually learned to accept and use horses over a period of about twenty years (ca. 1740—60). On the following pages we show some of Mr. Brown’s imaginative drawings illustrating this technological explosion, one that he likes to compare to the impact of the automobile on American culture a century and a half later. The culmination of the saga of the Plains Indians and the horse is epitomized by his sketch of a late-model Piegan warrior (above), fully mobilized, ready for battle on his tough and well-trained pony.