Location
Southeast and southwest flanks of the Sierrita Mountains, T. 18 S., Rs. 10 and 12 E.
Topographic Maps
Palo Alto Ranch and Twin Buttes 15-minute quadrangles.
Geologic Map
Wilson, Moore, and O'Haire, 1960, Geologic map of Pima and Santa Cruz Counties, scale 1:375,000.
Access
From Sahuarita on U.S. Interstate 19, it is about 15 miles west on improved roads to Sierrita Mountains. Dirt roads lead to placers on the flanks of the mountains.
Extent
Placer gold is found in two areas in the Sierrita Mountains-Ash Creek in the Papago district and Armargosa Arroyo in the Pima district.
Ash Creek drains the southwest flank of the Sierrita Mountains; the placer is located in the vicinity of the Sunshine-Sunrise group of mining claims (sec. 12, T. 18 S., R. 10 E.; sec. 7, T. 18 S., R. 11 E.; Palo Alto Ranch quadrangle). Placers were also found in Pascola Canyon, not identified on the topographic map.
The placer in Armargosa Arroyo and tributaries in the Tinaja Hills (southeast flank of the Sierrita Mountains) is in sees. 20, 21, 28, and 29, T. 18 S., R. 12 E. (Twin Buttes quadrangle). The topographic map shows "Tinaja Wash" in this area. The gold was recovered from gravels in the arroyo and its tributaries and from the thin soil on the hillside.
Production History
The recorded production from these placers is small, but the placers are said to have been worked before the discovery of gold in California and reportedly produced considerable amounts of gold before records were kept. Elsing and Heineman (1936, p. 98) attribute a placer production of $250,000 to the Papago district placers; this sum may be an estimate of the early production of the area.
Source
Unknown.
Literature
Allen, 1922: Location; placer-mining operations.
Browne, 1868: History; early date of placer mining.
Elsing and Heineman, 1936: Placer-production estimate for Papago placers.
Wilson, 1961: Location, production for Papago district. Location, placer-mining activity; accessory minerals in placers for Pima district.
