covers a vast portion of eastern Washington state, including parts of Whitman, Adams, Lincoln, and Spokane counties in Washinton, and Latah County in Idaho. It is bounded on the east by the Palouse range, which are really just the foot hills of the Clearwater Mountains. To the west of these are a series of buttes, which are of the same or similar geologic base as the eastern mountain range. Along the western border lie the Channeled Scablands, formed by repeated and large scale glacial flooding. The floods which carved the scablands carried with them tons of glacial silt which they deposited, forming the basis for the palouse hills, which cover the rest of the region. These are basically extensive sand dunes; the wind serving the same function as with sand dunes to transport and shape these glacial silts. If you want further technical/geologic explanation of the region, go ask a geologist.
Historically, the Palouse being a fertile and gentle-weathered sort of area, were pretty popular among the Native Americans, and among the tribes that made their homes there were the Nez Perce (heard of them, eh?) and the Palus, who gave their name to the region, and the horses they bread for plains living, the Appaloosa. It was also an appealing place for settlers, primarily due to the same reasons, so you'll probably get very different stories about the history of the area, depending on who you ask..
Currently the hills are almost entirely given over to farmland, where they produce mostly wheat and legumes, being the biggest producers of lentils in the country. (They even have a lentil festival.) Ecologically this is devastating. The region naturally gets very little rainfall, and the combination of heavy irrigation and the irregularly shaped and often steep hillsides causes drastic erosion problems, and other imbalances in soil makeup etc, and this doesn't even get into the decimation of native plant and animal species because of the heavy agricultural focus. If you want to know more, go ask an ecologist.
Aesthetically, the hills become emotion. They drive straight into the back of your head. They swallow you up and the wind howls past you, trying to pry you from its grip of teeth. And devils swirl by unable to touch you in the breast of the land. And the hills move on, they sweep and tumble. They mirror the wind. Their contour outlined in row after row of wheat or lentil or deep churned earth. It is a living topo map.
references:
http://www.wsu.edu/DrUniverse/palouse.html
http://www.ci.colfax.wa.us/History.htm
http://ceed.wsu.edu/watersheds/Palouse/History/phys_history.htm