The country to the north and east of the Warner Valley is a high volcanic plateau which has undergone considerable erosion.
 The Warner Valley was probably a similar high plateau before massive faulting dropped the valley floor and uplifted the land around it, forming high valley walls.
 The Warner Lakes formed in the valley bottom after the faulting stopped.

The Warner Valley is bounded by high escarpment walls on the east and west.
 The main line of perpendicular displacement is along the foot of the cliffs to the east of the Warner Lakes.
 This scarp feature is known as Hart Mountain.
 The main cliff face of Hart Mountain towers 3,600 feet (1,100 m) above the valley floor.
It runs the length of the valley, eventually being lost in a series of smaller fault scarps at the north end of the valley.
 These smaller scarps generally run from the east side of the valley to the northwest.
 The south end of the valley is more complex.
 In that area, the valley floor is bounded on three sides by perpendicular cliffs from 1,500 to 2,000 feet (460 to 610 m) high, the result of numerous fault events.
 These cliffs expose hundreds of feet of Miocene and Oligocene lava flows and ignimbrites, which include Steens basalt and various andesite, trachyandesite, and tuff flows.
 The mountain mass forming the western border of the South Warner Valley is a steep fault scarp.
 This cliff face rises over 2,000 feet (610 m) above the valley floor.

Warner Valley is an alluvial basin containing numerous lakes, remnants of a single great lake that covered the valley floor up to a depth of 200 feet (61 m) during the Pleistocene epoch.
 Today, steep cliffs rise above a chain of endorheic lakes.
The country to the north and east of the Warner Valley is a high volcanic plateau which has undergone considerable erosion.  The Warner Valley was probably a similar high plateau before massive faulting dropped the valley floor and uplifted the land around it, forming high valley walls.  The Warner Lakes formed in the valley bottom after the faulting stopped.
The Warner Valley is bounded by high escarpment walls on the east and west.  The main line of perpendicular displacement is along the foot of the cliffs to the east of the Warner Lakes.  This scarp feature is known as Hart Mountain.  The main cliff face of Hart Mountain towers 3,600 feet (1,100 m) above the valley floor. It runs the length of the valley, eventually being lost in a series of smaller fault scarps at the north end of the valley.  These smaller scarps generally run from the east side of the valley to the northwest.  The south end of the valley is more complex.  In that area, the valley floor is bounded on three sides by perpendicular cliffs from 1,500 to 2,000 feet (460 to 610 m) high, the result of numerous fault events.  These cliffs expose hundreds of feet of Miocene and Oligocene lava flows and ignimbrites, which include Steens basalt and various andesite, trachyandesite, and tuff flows.  The mountain mass forming the western border of the South Warner Valley is a steep fault scarp.  This cliff face rises over 2,000 feet (610 m) above the valley floor.
Warner Valley is an alluvial basin containing numerous lakes, remnants of a single great lake that covered the valley floor up to a depth of 200 feet (61 m) during the Pleistocene epoch.  Today, steep cliffs rise above a chain of endorheic lakes.
Warner Valley