Location
East flank of the Santa Rita Mountains, T. 19 S., Rs. 15 and 16 E.
Topographic Maps
All 15-minute quadrangles—Sahuarita, Empire Mountains, Mount Wrightson, and Elgin.
Geologic Maps
Drewes, 1971a, Geologic map of the Mount Wrightson quadrangle, scale 1:48,000.
1971b, Geologic map of the Sahuarita quadrangle, Pima County, scale 1:48,000.
Hill, 1910, Sketch map of the Greaterville, Arizona, placer camp.
Access
The Greaterville area is accessible by roads that lead 5 miles west from State Highway 83, about 8 miles north of Sonoita on the junction with State Highway 82.
Extent
The placers in the Greaterville district are found in streams that drain easterly from the Melendrez Pass area in the Santa Rita Mountains to the Cienega Valley. The deposits are in the southeastern part of T. 19 S., R. 15 E., and in the southwestern part of T. 19 S., R. 16 E. The gold-bearing gulches are, from north to south: Empire, Chispa, Colorado, Los Pozos, Hughes, Ophir, Nigger, and St. Louis Gulches, tributaries to Hughes; Louisiana, Graham, Sucker, Harshaw, Kentucky, and Boston. Placers were found not only in the gulch gravels but also in gravels on the hillsides and ridgetops between gulches. Hill (1910) describes the distribution of the goldbearing gravels in each gulch in detail, and, as his report is well known, I will only summarize his description.
In general, the gold is found in the lower 2 feet of angular gravel overlying bedrock and underlying less rich gravels; in places, the gold was concentrated in natural riffles in the sedimentary bedrock. The gold recovered ranged in size from flakes to large nuggets. Hill (1910, p. 20) states that the gold washed in 1909 ranged from small flakes to particles 0.1 inch in greatest dimension. Most of the largest nuggets were recovered during the early mining period in the district; at that time (1874-86) nuggets worth $1 to $5 (about 1 /2o-1/4 oz) were common, and one nugget weighing 37 ounces was found.
Production History
The early production is not accurately known. For gold recovered before 1900, estimates range from as high as $7 million to as low as $500,000. During the 20th century the placers have been worked continually by many individuals using rockers. Much of the placer ground has been reworked several times, but a considerable amount of gold is said to remain in the gravels. Various attempts have been made to mine the gravels in different gulches using hydraulic or dredge mining methods, but thickness of overburden made large-scale mining unprofitable. In 1948 a dragline shovel and dryland washing plant treated 90,000 cubic yards of gravel from Louisana Gulch, recovering 535 ounces of gold, an average of 21 cents per cubic yard (or 0.006 oz per cubic yard). This was the largest amount of gold recorded from the placers in any one year during the 20th century.
Source
The placer gold was derived from erosion of free gold-bearing veins genetically related to a quartz latite porphyry (dated at 55.7 ±1.9 m.y.) intrusive into Cretaceous sedimentary rocks. These veins are found near the heads of the gulches and have been mined for the gold content at the Yuba, St. Louis, and Quebec mines.
Literature
Allen, 1922: Virtually repeats information described by Hill (1910). Adds information about placer-mining operations in 1914.
Black, 1890: Past placer-mining activity.
Blake, 1898: Describes late Pleistocene bison remains found in placer deposit.
1899: Detailed description of placers. Includes location; names of placer gulches; size of nuggets; placer-mining operations; source of placer gold; repeats part of earlier description by Black (1890). Describes separately size of nuggets found in the ""Smith district"" now known as Greaterville.
Burchard, 1882: Placer-mining activity at Hughes Gulch is noted.
1884: History; production.
1885: History; size of nuggets; placer-mining operations; techniques; production.
Drewes, 1970: Describes mineralization in district; distribution of gold.
Gardner and Johnson, 1935: Placer-mining techniques by drift mining.
Heikes and Yale, 1913: Thickness of placer gravels; gold values per cubic yard; fineness of gold; production from 1903 to 1912.
Hill, 1910: Detailed description; extent, thickness, and character of gravels; size and fineness of gold; bedrock geology; placermining techniques, operations; production.
Hinton, 1878: Notes placer occurrence; size of large nugget.
Koschmann and Bergendahl, 1968: Location; source; production.
Maynard, 1907: Detailed description of sampling. Grades of gravel given for each gulch.
Randolph, 1901: Production estimates.
Raymond, 1875: Reports placer ground on the east side of the Santa Rita Mountains; names prospectors who made discoveries.
1877: Repeats information of newspaper article describing new discovery of placer gold at Greaterville; size of nuggets; methods of mining district; refers to as ""Smith district""; does not locate district; names miners.
Root, 1915: Placer mining in 1914; average grade of gravel; depth of water ""sufficient for dredging purposes.""
Schrader, 1915: Virtually repeats Hill's (1910) description.
Wilson, 1961: Placer-mining activity during the period 1874-1948; history; quotes Schrader (1915); production; source.
