Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Saddle Mountains consists of an upfolded anticline ridge of basalt in Grant County of central Washington state. The ridge, reaching to 2,700 feet, terminates in the east south of Othello, Washington near the foot of the Drumheller Channels. It continues to the west where it is broken at Sentinel Gap (a water gap through which the Columbia River passes) before ending in the foothills of the Cascade Mountains. The top exposed layer of Columbia River Basalt Group basalt in the Saddle Mountains is the Saddle Mountain Basalt, which ranges from 120 - 240 meters (400 - 800 feet) in thickness and is interspersed by sedimentary layers of the Ellensburg Formation.