Signs warn against trespassing at a well injection site operated by Bridgeport Tank Trucks LTD., Saturday, June 21, 2014, in Azle, Texas. Earthquakes used to be unheard of on the vast stretches of prairie that unroll across Texas and Oklahoma. But in recent years, temblors have become commonplace. Oklahoma recorded 145 of them just between January and the start of May. (AP Photo/Tony Gutierrez)
Featured Photo Galleries
