NM21-765-016 Amarillo, Texas, U.S.A Spring 1996 Visible in this photograph is some of the urban infrastructure--airport, highways, street patterns, central business district--of Amarillo, the largest city in the Texas panhandle. The only deviation from the flat and featureless Texas high plains is the southeast-flowing Prairie Dog Town Fork of the Red River, which has created picturesque Palo Duro Canyon. The majority of fluvial erosion occurred during a much wetter geological time; however, erosion still results from downpours in this semiarid climate. Most of the countryside surrounding Amarillo, except for the north and northwest, evidences widespread agriculture.