At mile post #116 you can see the San Pedro River, and you will also be entering the town of Mammoth. Mammoth took its name from the Old Mammoth Mine, located above the town in the late 1800's. It was said the gold ore deposits were of mammoth proportions, hence the name. In 1895 the Mammoth Mine changed hands while a new system of milling was introduced. This was the beginning of the last gold mining revival in Arizona. Mammoth enjoyed renewed importance in 1936 when molybdenum production began. It is located in the San Pedro valley along with San Manuel six miles south, and with Oracle, make up the tri-community area.