Street and highway grid patterns in metropolitan Phoenix are visible in this photograph. The population of this arid, hot region grew rapidly in the 1960s and 1970s as Arizona emerged as an industrial state. Northwest of downtown Phoenix, the distinctive, curving lines of the golf course and lakes of the Sun City retirement community are apparent; the dual runways of Phoenix’s Sky Harbor International Airport near the southern edge of the city are barely discernible. Large, rectangular, cultivated field patterns can be distinguished west of the city. South of Phoenix, South Mountain and the braided stream channels of the Gila River can be identified.