Why is there little farming and no ranching in the mountains and basins?

There are many potential reasons why there is little farming and no ranching in the mountains and basins. The most obvious being that there is considerable slope differences in these areas. A change in slope is prone to soil erosion, which limits both farming and ranching. It would be difficult to grow crops on an area with extreme slopes. Also, ranching typically requires grazing food sources such as grasses. These grasses are also not effective at protecting a mountain slope from erosion (at least not as effective as more woody plants). Basins are normally found at the base of mountains. The problems associated with slopes on mountains also affect the basin as this is where the eroded soil and plant material end up.