Answer to Question 1
The student should take the suggestion of comparing climactic patterns in a northern and southern city. But, in general, there are four different climate realms in the Intermontane regionsubhumid, semiarid, moderately arid, and extremely arid zoneswith differences in precipitation as the determining factor.
The subhumid realm, according to the text, includes mountainous areas in eastern Oregon, Washington, and Idaho, and tends to be places at relatively higher elevations.
The semiarid realm includes most of the Columbia Plateau including the Palouse region.
The moderately arid realm is the largest, and includes most of the Great Basin of Nevada and Utah.
The extremely arid realm includes the Mojave Desert, Death Valley, and other very dry places in the Intermontane region.
Answer to Question 2
The waters from the Great Missoula flood scoured the landscape, exposing rock and carving out deep canyons to find its way eventually to the pacific.