Author's note: The most productive placers in Arizona are in the high mountainous region of south-central Yavapai County. Most of the placers are concentrated on the slopes of the Bradshaw Mountains in the vicinity of many small lode deposits. Because of the large number of small mining districts that include parts of gold-bearing streams. I have grouped the placers on the basis of drainage areas rather than formal mining districts
South flank of the Bradshaw Mountains, Tps. 7-10 N., R. 1 E.; Rs. 1 and 2 W.
Bradshaw Mountains 30-minute quadrangle; Prescott 2-degree sheet, Army Map Service; Crown King 15-minute quadrangle (covers only N 1/2 of quadrangle); Governors Peak 7 1/2-minute quadrangle.
Arizona Bureau of Mines, 1958, Geologic map of Yavapai County, scale 1:375,000.
Lindgren, 1926, Geologic map of the Bradshaw Mountains quadrangle, Arizona (pi. 2), scale 1:125,000.
Light-duty roads lead northwest to Humbug Creek from State Highway 69 north of Lake Pleasant.
Placers are found in many of the creeks that drain the south flank of the Bradshaw Mountains. Humbug, French, and Cow Creeks (Tps. 7-9 N., R. 1 W., R. 1 E.) reportedly contain placer gold throughout 20 miles of the drainage area. Buckhorn Gulch, Castle Creek, and small tributaries have been placered along the upper reaches in the vicinity of Copperpolis (T. 8 N., R. 2 W.).
The production from the placers found in the Humbug Creek drainage area is generally listed by the U.S. Bureau of Mines under Humbug, Tip Top, Tiger, Silver Mountain, Castle Creek, and White Picacho districts. Most of the placer production has been small and intermittent. During the 1800's, placers in Rockwall, Carpenter, and Swilling Gulches, tributaries to Humbug Creek (T. 8 N., R. 1 W.-R. 1 E., Bradshaw Mountains quadrangle) were reportedly very productive but were exhausted early in the 1900s.
During the 1890's, the Humbug Hydraulic Mining Works planned large-scale placer mining on lower Humbug Creek and constructed a dam in sec. 6, T. 7 N., R 1 E., (Governors Peak quadrangle). This enterprise met with failure because the size of the gold was too small for the recovery methods used. The Star Placer on Humbug Creek (sec. 13, T. 8 N., R. 1 W.) and the Horseshoe placer (unlocated) on French Creek were worked after 1900.
Small amounts of placer gold were recovered from Buckhorn Gulch, Castle Creek, American Gulch, and Todos Santos Creek (unlocated, White Picacho district) . The John D. placer, on Castle Creek (sec. 9, T. 8 N., R 2 W.), has been worked in the 20th century. Plans were made to dredge parts of Buckhorn Gulch, a tributary to Castle Creek, but apparently the operation did not materialize.
Gold placers along the upper reaches of Humbug Creek and especially in Carpenter, Swilling, and Rockwall gulches, were probably derived from gold veins that intersect and offset rhyolite porphyry dikes (described by Lindgren, 1926, p. 179); association with these dikes is considered indicative of a "Laramide" age for gold mineralization in the Bradshaw Mountains.
Gold placers along Castle Creek and tributaries were derived from Precambrian ore deposits that predominate in that area.
Allen, 1922: Placer operations in the 1890's; reasons for failure.
Burchard, 1885: Reports placer mining on Coso Creek and tributaries (unlocated).
De Wolf, 1916: Reports activity at Humbug Creek.
Lindgren, 1926: Notes production from tributaries to Humbug Creek.
Wilson, 1961: Extent and thickness of gold-bearing gravels; distribution of gold in gravels; placer-mining activity during the period 1932-33.