In 1918 Earl Q. Gray of Ardmore, Oklahoma established the Gray Ranch Company/Pennington Creek Oklahoma Hunting Ranch in Mill Creek, Oklahoma.

Earl Q. Gray recognized the grazing potential of this limestone area of Johnston County which was further enhanced by its proximity to the headwaters of the spring-fed stream, Pennington Creek, that runs for several miles through our 9,400-acre property. Its ownership gave him what he regarded as the best year-round grazing and Hunting Ranch in the state of Oklahoma. Under the Walking G and Q Bar brands, Earl Q. Gray ran cattle here until his death in 1979.