The last barrier to growth was breached when, in the 1960s, air-conditioning was introduced to Arizona's desert regions. Population and industry in urban centers such as Phoenix skyrocketed. This rapid growth continues to the present day. Today, Arizona boasts a population of almost 5 million residents. Arizona also has a long history in mining and agriculture.
Cotton is Arizona's principal crop.
Other primary crops are citrus, hay, lettuce, cauliflower, broccoli and melons. Arizona is renowned for its natural beauty, varied recreational activities and diverse cultures. Over 22 national parks, monuments and wildlife preserves. 25 state historical and recreational parks. 67 natural and man-made lakes.