_Munro Area, John Day Fossil Beds State Park._ The valley of the John
Day River has been widened to nearly five miles by erosion in the John
Day Formation. Large tilted slide blocks of the John Day Formation and
basalts jumbled together show how important landsliding of soft beds
under hard rocks can be in widening valleys.
[Illustration: Fig. 6.—Sheep Rock from Thomas Condon viewpoint.]
Here one can appreciate the regularity and extent of basalt flows of the
flood or plateau type, which form the Columbia Plateau. Individual flows
have been traced 100 miles. Travelers will see few other rocks between
here and The Dalles, Wenatchee, Pendleton, or Spokane as they cross
parts of the Columbia Plateau.