Along the ordinary plains river, such as the Little Missouri, where I ranched for many years, there are three entirely different types of country through which a man passes as he travels away from the bed of the river. There is first the alluvial river bottom covered with cottonwood and box-elder, together with thick brush. These bottoms may be a mile or two across, or they may shrink to but a few score yards. After the extermination of the wapiti, which roamed everywhere, the only big game animal found in them was the whitetail deer. Beyond this level alluvial bottom the ground changes abruptly to bare, rugged hills or fantastically carved and shaped Bad Lands rising on either side of the river, the ravines, coulees, creeks, and canyons twisting through them in every direction. Here there are patches of ash, cedar, pine, and occasionally other trees, but the country is very rugged, and the cover very scanty. This is the home of the mule-deer, and, in the roughest and wildest parts, of the bighorn. The absolutely clear and sharply defined line of demarkation between this rough, hilly country, flanking the river, and the alluvial river bottom, serves as an equally clearly marked line of demarkation between the ranges of the whitetail and the mule-deer. This belt of broken country may be only a few hundred yards in width; or it may extend for a score of miles before it changes into the open prairies, the high plains proper. As soon as these are reached, the prongbuck’s domain begins. As the plains country is passed, and the vast stretches of mountainous region entered, the river bottoms become narrower, and the plains on which the prongbuck is found become of very limited extent, shrinking to high valleys and plateaus, while the mass of rugged foothills and mountains add immensely to the area of the mule-deer’s habitat.