Quartzsite Mining History

The famous placers that surround the town of Quartzsite are known to have been successfully worked by individual prospectors since the 1860's and it continues to this day. Gold placers are found in the Dome Rock Mtns west of Quartzsite, in the Plomosa Mtns east of Quartzsite and scattered on the La Posa Plain which lies in between the two ranges. Both mountain ranges are highly mineralized and contain numerous lode mines bearing many different types of valuable ore.

Placer information:
This information is taken directly from US Geological Survey Bulletin 1355, Placer Gold Deposits of Arizona, by Maureen G. Johnson, 1972

La Cholla, Middle Camp & Oro Fino Placers

Location: East side of the Dome Rock Mountains, Tps 3N and 4N, R20W

Access: From Quartzsite it is about 5 miles west on US Highway 60-70 ( I-10) to Dome Rock Mountain. Dirt roads lead from the highway to adjacent placers

Extent: Placers are found on the east side of the Dome Rock Mountains in three localities. La Cholla placers, located south of US Highway 60-70 (I-10) in an area 4 to 5 miles long from east to west. (NE1/4 T3N, R20W); at the southern base of the Middle Camp Mountain (approximately SW 1/4 T4N R 20W); Oro Fino placers, located north of US Highway 60-70 (I-10) and southeast of the Middle Camp placers (SE 1/4 T 4N R 20W).

History: The placers on the east side of the Dome Rock Mountains have been worked intermittently since the 1860's. The placer camps are usually considered to be part of the Plomosa mining district and production records are usually grouped with the Plomosa placers, 12 miles east. The deposits at La Cholla and the Middle Camp have been worked on a small scale throughout this century. From the 1930's until 1941, the La Cholla placers were the most active in the area; large-scale operations by the La Posa Development Co. at the Arizona Drift mine during the period 1939-41 accounted for most of the placer production. This company worked a channel on bedrock that was 6 feet thick and 50-150 feet wide at a depth of 140 feet. No estimates of the average value of the gravels worked by this operation have been found, but the gravels worked in an earlier operation contained in places as much as 1 ounce of gold per cubic yard, and the tailings were valued at 85 cents per cubic yard.

Source: Gold-quartz veins in the mountains immediately adjoining the placer deposits are the source of the placer gold.

Plomosa District

Location: West side of the Plomosa Mountains, Tps 3N & 4N R 18W, T2N R17W

Access: From Quartzsite it is about 5 miles southeast on dirt roads to placer area.

Extent: The plomosa placers are found at the western edge of the Plomosa Mountains in and near Plomosa Wash south of Scaddan Mountain. (Tps 3N & 4N, R18W) The extent of the placers in the Plomosa district is not known, but some reports indicate that gold-bearing gravels are found for about 3-4 miles along the western edge of the mountains. Most large-scale placer activity was apparently concentrated in secs. 3 and 4, T3N R18W, near the old town of Plomosa. Small placers were apparently worked in Cave Creek in the southern part of the range (T2N R17W)

History: The Plomosa placers were worked in the early 1860's about the same time as the La Paz placers. Early production is unknown, but the extensive diggings remaining from the early workers indicate that production was large. The Plomosa placers were actively sampled and mined during the 1910's by companies using large-scale drywashing machines; these operations attracted much attention from mining men at the time, and the resulting literature described the gravels and mining techniques in great detail. Production records indicate that these operations were not a commercial success. Various reports of the average value of the gravels claim values as high as $20 per yard in placer gold, but more reasonable estimates range between 71 cents to $1.77 per yard. The placers worked by the Yuma Consolidated Co. and the Plomosa Placer Co. during the period 1915-16 were cemented gravels as thick as 140 feet; the gold was concentrated at various horizons in the gravels. The placers were steadily mined by individual drywashers until the 1950's.

Source: Gold -bearing veins occur in the metamorphic rocks in the immediate vicinity of the placers and are considered to be the source of the gold in the gravels.