A 1974 souvenir of the Bertha Rogers No. 1 well, which sought natural gas almost six miles deep in Oklahoma’s Anadarko Basin. — aoghs.org
The Lone Star Producing Company 1–27 Bertha Rogers hole or well was an oil-exploratory hole drilled in Washita County, Oklahoma in 1974, and was the world's deepest hole until it was surpassed in 1979 by the Kola Superdeep Borehole, dug by the USSR. — wikipedia