1540: Captain Juan Hernando de Alarcon leaves Acapulco, Mexico to sail north until he reached the headwaters of the Gulf of California, thus becoming the first white man to explore beyond the mouth of the Colorado River.

1869: Camp Hualapai is established as Camp Toll Gate. The camp is established in the Aztec Mountains overlooking Walnut Creek. The name was changed to Camp Hualapai on October 4, 1870. The post was abandoned on July 31, 1873.

1916: Tucson motorists set a record for traveling to Phoenix: 3 hours, 35 minutes.

1922: The last federal troops leave Fort Apache just as the first Lutheran mission is dedicated there with the baptism of 100 Apaches.

1979: Aden Meinel, founding director of both Kitt Peak and the University of Arizona's Optical Sciences Center,  begins operation of a revolutionary Multiple Mirror Telescope at Mount Hopkins, south of Tucson. It is the third-largest optical telescope in the world at the time of its dedication, and it remains in service until 1998.

Want to share an important event from Tucson's history? Email it to krumore@azstarnet.com.