The name "Oracle" comes from early prospectors. Albert Weldon came to the area looking for gold and silver.
He and some other companions named their first mine The Oracle after the ship Weldon had traveled on. The community was later named after its first mine, and thus, indirectly, after a ship.
The community began to grow in the late 1870s, as gold and silver were discovered, and the Christmas and New Year mines opened. By 1880, a post office had been established.
The community also became a retreat for people suffering from tuberculosis. The Acadia Ranch – built in Oracle in 1882 by Edwin S. and Lillian Dodge – was, during this time, a sanitorium.
At an altitude of 4,500 feet (1,400 m), Oracle's vegetation consists of mostly emory oak (Quercus emoryi) and grasses. In January, the average high temperature is 56 °F (13 °C) with a low of 35 °F (2 °C). In July, the average high temperature is 92 °F (33 °C) with a low of 67 °F (19 °C). Annual precipitation is 18 inches. Rainfall increases during July and August, due to the monsoon effect. Snowfall varies.
Oracle is a census-designated place (CDP) in Pinal County, Arizona, United States. The population was 3,686 at the 2010 census.
Buffalo Bill Cody owned a mine in Oracle briefly and, in 1911, appeared as "Santa" for a group of local children. The community is near the location of Biosphere 2. Oracle was also the postal address for environmentalist author Edward Abbey, who never lived in the town but visited often. Oracle is becoming a bedroom community for Tucson, Arizona, but large-scale development is opposed by many residents.
Oracle State Park is adjacent. The Arizona Trail passes through the Park and community. Oracle is the gateway to the road up the "back side" of Mount Lemmon, which starts off of American Avenue and currently offers a secondary route to the top. Prior to the construction of the Catalina Highway on the opposite side of the Santa Catalina range, the Oracle Control Road was the only road access to the mountain community of Summerhaven.