Late afternoon in the piƱon and mesa landscape of southern New Mexico. The temperature on July 29, 1967, has just slipped below 100 degrees as GSX, the Golden State Express, otherwise known as #992, heads for El Paso behind Rock Island U25B 202. This train, which is on SP rails, has been climbing for 35 miles since passing under the Santa Fe at Vaughn and will top the grade a few miles further in Corona, at 6,667 feet highest point on the Golden State Route. Rock Island power here runs through from Kansas City to El Paso.