The valleys of the principal streams are deeply eroded; bluffs are common along their borders, and buttes elsewhere on the plains.
Taylor volcano (11,389 ft.), which is surrounded by lava tables and some of the most wonderful volcanic buttes in the world.
It is dominated by high mountains, gashed by superb canyons of rivers, scarred with dry gullies and washes, the beds of intermittent streams, varied with great shallow basins, sunken deserts, dreary levels, bold buttes, picturesque mesas, forests and rare verdant bits of valley.
Its surface consists of a thick sheet of pumiceous sand and dust, from which arise occasional buttes and mesas.
This plateau, however, is not a plain, but contains many buttes and mesas and isolated mountain ranges rising from 1000 to 8000 ft.