Location
Along the San Francisco River from Dorsey Gulch south to the junction with the Gila River, Tps. 4 and 5 S., Rs. 29 and 30 E.
Topographic Maps
Clifton and Guthrie 15-minute quadrangles.
Geologic Maps
Lindgren, 1905a, Geologic map and sections of the Clifton-Morenci district (pi. 1), scale 1:62,500 (see also Lindgren, 1905b).
Wilson and Moore, 1958, Geologic map of Graham and Greenlee Counties, scale 1:375,000.
Access
Light-duty road parallels San Francisco River near and north of Clifton. Dirt roads lead from U.S. Highway 666 to various points along the lower San Francisco River south of Clifton.
Extent
The placer deposits that occur along the course of the San Francisco River are logically divided into two groups. In the part of the river north of Clifton, the gold is found in ancient river gravels 50-60 feet above the level of the present riverbed, from the vicinity of Dorsey Gulch (sec. 5, T. 4 S., R. 30 E., Clifton quadrangle)south to the vicinity of Clifton (sec. 30, T. 4 S., R. 30 E.) The placers in benches of the river near Oroville (sec. 7, T. 4 S., R. 30 E.) have attracted the most attention.
Here, the richest goldbearing layers occur in thin pay streaks in channels at or near bedrock on the benches above the riverbed. The Bokares placer, 4 miles north of Clifton at Evans Point (sec. 6 or 7, T. 4 S., R. 30 E.), was also actively mined.
South of Clifton, the river is curved and flows between bluffs of hard Gila Conglomerate. Gold is contained in old river gravels resting on the conglomerate in some of the curves. The Smuggler placer mine is at a bend in the San Francisco River in sec. 14, T. 5 S., R. 29 E. (Guthrie quadrangle); the gravels here contained much fine gold.
Placers mined by the ""Frisco Placer Mining Company"" in the early 1900's are probably located in sec. 31, T. 5 S., R. 29 E. (Guthrie quadrangle) , 8 miles downstream from Clifton. The gravels at this placer deposit are 3-12 feet thick.
Production History
The placers were discovered in the 1870's and were actively prospected and developed during the 1880's. At that time, much money was spent to develop pipelines and water supplies to mine the gravels above Clifton by the hydraulic technique; the operations were not a financial success, although a fair amount of gold was recovered. The deposits were mined more or less continuously until the 1940's; small-scale mining techniques were used, the men frequently tunneling through the gravels to reach the richest parts near bedrock.
The production statistics here are, as for the Clifton-Morenci district, difficult to isolate from those of other placer districts in Graham and Greenlee Counties; but the bulk of the recorded production for the counties was derived from the placers along the San Francisco River.
Source
The placer gold in the San Francisco River above Clifton was derived from small gold-bearing veins, associated with porphyry dikes, that crop out in Dorsey and Colorado Gulches (for example, Colorado, Black Prince, and Golden Eagle veins) and were once mined for gold. The gold in the river south of Clifton was probably derived from these veins and from the small gold veins around Morenci that were the source of gold in the Clifton-Morenci placers.Literature
Allen, 1922: Quotes Lindgren (1905a).
Blake, 1899: Location; problems connected with large-scale placermining operations.
Burchard, 1882: History of discovery; placer operations in 1881. 1883: Placer-mining developments; production. 1884: Location; describes depth of placer gravels.
Dinsmore, 1911b: Operations of Frisco Placer Mining Co.; history; depth of gravels; value of placer gravels.
Hamilton, 1884: Repeated from Burchard (1884).
Lindgren, 1905a: Failure of past hydraulic operation; source of placers.
1905b: Location, age, and source of placer gravels.
Mining Journal, 1938b: Placer-mining operations at Bokares and Smuggler placer.
Mining Reporter, 1906: Location; past mining operations.
Trippel, 1888: Production for 1887.
Wilson, 1961: Location; characteristics of gravels; size of gold particles; placer operations in 1933.
