Tucson has been continuously settled for over 12,000 years. It celebrates a diversity of cultures, architecture, and peoples. Yet, it is one of the "Mega-Trend" cities of the 21st Century: the Optics Valley, premier health services center for the Southwest, the astronomy center of the world, home of a premier research institution - University of Arizona, and a tourism destination. Tucson, too SAHN or TOO sahn, is one of the oldest towns in the United States. Tucson was orginally an Indian village called Stook-zone, meaning water at the foot of black mountain. Hugo O'Conor established the Tucson Presidio in 1775. August 20th, 1775 is considered Tucson's birthday. Spanish settlers arrived in the area in 1776. Tucson officially became part of the United States with the Gadsden Purchase of 1854. Tucson served as capital of the Arizona Territory from 1867 to 1877. Tucson boasts the best of both worlds...the progress and innovation of a metropolitan community and the friendly, caring atmosphere of a small town. Tucson's rich cultural heritage centers around a unique blend of Native American, Spanish, Mexican and Anglo-American influences. Blessed with the natural beauty of the Sonoran Desert and an unsurpassed climate of 360 sunny days a year, Tucsonans embrace a rare lifestyle and are committed to preserving that quality of life. Tucson's climate varies from the 2400 foot desert basin to the 9100 foot forests of the Santa Catalina mountains. The City's dry desert air and winter sunshine make it a popular health and winter resort. The City is home to the University of Arizona and Davis-Monthan Air Force Base. The City's industries include electronics and missile production. Tucson is the seat of Pima County and has a Council-Manager form of government. The Tucson metropolitan area supports over 750,000 residents. As metropolitan Tucson continues to grow by nearly 2,000 new residents each month, the challenge of meeting citizen expectations also increases. The City of Tucson is committed to providing quality municipal services which promote a healthy community, offer opportunities for participation and leisure and enable citizens to prosper at work and at home.