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
North flank of the Bradshaw Mountains and the south side of Lonesome Valley, Tps., 13 and 14 N., R. 1 W.; T. 14 N., R. 1 E.
Prescott and Mount Union 15-minute quadrangles.
Anderson and Blacet, 1972b, Geologic map of the Mount Union quadrangle, Yavapai County, Arizona, scale 1:62,500.
Krieger, 1965, Geologic map and sections of the Prescott quadrangle, Arizona, (pi. 1), scale 1:48,000.
From Prescott, State Highway 69 east parallels the lower course of Lynx Creek, and light-duty roads lead south from State Highway 69 at Prescott to many points along the upper reaches of Lynx Creek.
Placers occur along the entire length of Lynx Creek from near the headwaters at Walker, 7 miles southeast of Prescott, downstream to the junction of Lynx Creek with the Aqua Fria River, 13 miles east of Prescott.
The placers along the upper reaches of Lynx Creek (in the Walker district) occur in the main creek and along its tributaries from near Walker (sec. 34, T. 13 N., R. 1 W., Mount Union quadrangle) downstream for a distance of about 8 miles to the lower dam area (sec. 22, T. 14 N., R. 1 W., Prescott quadrangle). This part of Lynx Creek flows across Precambrian rock, and the gold occurs in thin gravels on narrow benches or bars.
The placers in lower Lynx Creek occur in the east-trending part of the creek from the area around the lower dam, east to the junction with the Aqua Fria River (sec. 34, T. 14 N., R 1 E., just east of the Prescott quadrangle). Gold occurs in the recent alluvium at the bottom of the steep-walled gulch cut into Tertiary conglomerate. The placer gravels attain a minimum width of more than one-eighth of a mile and have a thickness of 8-24 feet; a rich pay streak 4 feet thick was found 2 feet above the conglomerate bedrock.
An area called the Nugget Patch, south of the lower dam on Lynx Creek (sec. 3, T. 13 N., R. 1 W., Prescott quadrangle), is said to contain gold in black sands that were probably derived from quartz veins in the underlying Precambrian gabbro (Krieger, 1965, p. 114).
Lynx Creek is the most productive gold-bearing stream in Arizona, although other districts (La Paz, Yuma County; Weaver, Yavapai County) have yielded more gold from alluvial fans, flats, and arroyos. The Lynx Creek placers were discovered in May 1863 by Sam Miller and four other prospectors of the group led by Captain Joe Walker. Sam Miller reportedly panned $4.80 in gold from a gravel bank along Lynx Creek; on May 10, 1863, the party organized the first mining district in Yavapai County, which they called the "Pioneer District."
The Walker quartz mining district was formed November 24, 1863. Production from the Lynx Creek placers before 1900 is generally estimated at about $1 million, although some writers estimate $2 million.
During the 20th century the placers in the lower section of Lynx Creek have been the most actively mined. Large-scale placer mining was done by dredges operating along 5 miles of lower Lynx Creek from the lower dam in sec. 22, T. 14 N., R. 1 W., to the vicinity of Fain's Ranch in sec. 28, T. 14 N., R. 1 E. (Prescott quadrangle). The Calari Dredging Co. worked placer ground in 1933 below the lower dam that averaged 32 cents per cubic yard. In late 1939 the Rock Castle Placer Mines Co. used a dryland dredge to work the bench gravels in this area.
From 1934 to 1940 (in particular the years 1938-39) the Lynx Creek Placer Mining Co. worked the gravels on the Fitzmaurice property, which extends from sees. 22-24, T. 14 N., R. 1 W., through sec. 19, T. 14 N., R. 1 E.; this dredge was the largest single producer in Arizona.
Most of the placer mining in the area of upper Lynx Creek was small-scale rocking and sluicing, but a few larger scale placer operations were attempted, especially in that part of upper Lynx Creek just downstream from the old Highway Bridge (NW 14 sec. 33, T. 14 N., R. 1 W.). During the period 1940-41 gravels were worked in the area called Bigelow Flat to about half a mile below the bridge, a distance of about 3 miles.
The placer gold in Lynx Creek was derived from numerous widely scattered small gold-quartz veins in adjacent parts of the Bradshaw Mountains. Mineralization in the Bradshaw Mountains is both Precambrian and Laramide in age, and placers have been derived from veins of both ages. In the Walker area, the gold-quartz veins are associated with a small stock of granodiorite that recent work has shown to be of Laramide age (64 m.y.; Anderson, 1968, p. 1169).
Most of the gold in Lynx Creek is thought to have been derived from the gold veins in the Walker area. The gold found along the creek varies from coarse nuggets to 4 ounces in the upper reaches of the creek to fine gold along the lower reaches of Lynx Creek. The gold-silver ratio in the nuggets increases downstream.
Allen, 1922: Location; production; placer-mining operations during the periods 1907-9 and 1918-19.
Blake, 1899: Location; placer-mining operations; problems; gold values per cubic yard.
Burchard, 1882: Production estimate (1863-81).
1884: Brief history of early placer mining; locates placer ground near lode mines on upper Lynx Creek.
1885: Production estimates and production for 1884.
De Wolf, 1916: Reports four hydraulic giants installed at Lynx Creek.
Gardner and Johnson, 1935: Depth of gravel; placer-mining operations on upper Lynx Creek.
Gardner and Allsman, 1938: Lists—placer-mining techniques; depth and characteristics of gravel mined; depth of bedrock mined; percent of gold recovery.
Koschmann and Bergendahl, 1968: History; placer-mining operations; production.
Krieger, 1965: History; location of placer-mining operations; bedrock geology.
Lindgren, 1926: History; production; extent of placers, character and value of gold; source.
Raymond, 1872: Walker district—extent of placers; placer-mining problems on upper Lynx Creek.
Wilson, 1961: Location; history; production; dredging operations to 1949. Small-scale operations in 1933; geology of gold in gravels.
Wood, 1929: History of placer discovery.