With the exception of an area in the extreme western part, which drains into the Rio Verde, practically all of this portion of the reserve lies along the upper border of the basin of the Little Colorado. It is a continuation of the general easy slope which begins about 5,000 feet on the river and extends back so gradually at first that it is frequently almost imperceptible, but by degrees becomes more rolling and steeper until the summit is reached at an altitude of from 6,000 to 9,000 feet. The reserve occupies the upper portion of this slope, which has more the form of a mountainous plateau country, scored by deep and rugged canyons, than of a typical mountain range. From the summit of this elevated divide, with the exception of the district draining into the Rio Verde, the southern and western slope drops away abruptly several thousand feet into Tonto Creek Basin. The top of the huge escarpment thus formed faces south and west, and is known as the rim of Tonto Basin, or, locally, "The Rim." From the summit of this gigantic rocky declivity is obtained an inspiring view of the south, where range after range of mountains lie spread out to the distant horizon. The rolling plateau country sloping toward the Little Colorado is heavily scored with deep box canyons often hundreds of feet deep and frequently inaccessible for long distances. Most of the permanent surface water is found in these canyons, and the general drainage is through them down to the lower plains bordering the river. The greater part of this portion of the reserve is covered with yellow pine forests, below which is a belt, varying greatly in width, of piñons, cedars and junipers, interspersed with a more or less abundant growth of gramma grass. This belt of scrubby conifers contains many open grassy areas, and nearer the river gives way to continuous broad grassy plains. Nowhere in this district, either among the yellow pines or in the lower country, is there much surface water, and a large share of the best watering places are occupied by sheep owners. The wild and rugged slopes of Tonto Basin, with their southerly exposure, have a more arid character than the area just described. On these slopes yellow pines soon give way to piñons, cedars and junipers, and many scrubby oaks and various species of hardy bushes. The watering places are scarce until the bottom of the basin is approached. Tonto Basin and its slopes are also occupied by numerous sheep herds, especially in winter.