My Uncle had a farm in Sheridan Co. We visited him & his family a few times...mostly when I was a "young Whipper-snapper" ! (1950s ) We'd always pass through Valentine (Cherry Co.) where the July temperature was always over 100 degrees...DUST for DAYS ! I remember jumpng in the back of a pickup truck to help stop a brush fire on my Uncle's farm and riding over some very sandy hills...so I'd say at the very least : Cherry & Sheridan Counties. Paul