A gap between the Uintas and the main body of the Rocky Mountains marks the drainage area of the Colorado's major tributary, the _____ River, which extends northward into Wyoming. Only the gently sloping surface of the Great Divide Basin separates this river from the headwaters of the North Platte. Green The Navajo acquired the use of the rifle and the horse, and learned to herd sheep, from the: Spanish As elsewhere in the West, vegetation and land use in the Sonoran Desert are determined largely by elevation and: slope aspect Hopi religious beliefs and social organizations, as well as their matrilocal residence pattern and their habits of egalitarianism and village autonomy, have attracted generations of _____ to the mesa-edge villages. cultural anthropologists By the time the Pacific Railroad Act was passed in 1862, the chosen route crossed _____, not New Mexico and Arizona. Wyoming and Utah Geologically, the Sonoran Desert is part of the _____ section, and thus it exhibits the same characteristic topography of low, widely spaced mountain ridges. Basin and Range Air settling from the Mojave Desert downslope through _____ Pass and into the Salton Trough creates a rush of wind sufficient to turn the blades of more than 2,500 wind turbines placed there to generate electricity. San Gorgonio The _____ Mountains are an uplifted maze of volcanic peaks and glaciated mountain valleys that pose an extremely difficult topography to cross and effectively isolate