To gain some insight into Arizona's future, we need to look back on the past. Who would have thunk it? The average life span of an American in 1900 was 47; today it's 78. Less than 14 percent of the homes in the United States had a bathtub, while around 8 percent had a telephone.

One in 10 adults couldn't read or write, and only 6 percent of all Americans had graduated from high school.

Ninety-five percent of all births took place in the home and 90 percent of all physicians had no college education. The leading causes of death were pneumonia and influenza, tuberculosis and diarrhea.

The population of Las Vegas was 30, and there were about 230 murders reported in the U.S. annually.

Last but not least, most women washed their hair only once a month using borax or egg yolks. It was 1930 when Dr. John Breck developed a shampoo gentle enough to wash more often.

In Arizona, Tucson and Bisbee were rivals for the title of largest city in the territory.

Who could have foreseen such creations as the radio, television, computers and the myriad other devices we take for granted today? Considering the multiple factors resulting from new technology, the possibilities are endless over the next 50 years.

One thing is certain: The population is going to increase, and there's where Arizona is holding an ace card.

Only 17 percent of the state is private land. Development may max out most of it, but let's hope Arizonans have the common sense to provide preserves to give urban folks some breathing space.

More than 80 percent of Arizona is either Indian, state or federal land; much of it is accessible to the public. So no matter how many people are residing in the state in 2062, we'll always have our open spaces; places far from the maddening crowds; places that belong to everybody and nobody.

Some of these areas are blessed with the most beautiful scenic lands in the country. They are our sanctuaries. Thank God for that!

Marshall Trimble is Arizona's official state historian. He was born in Mesa.