GEOLOGIC MAPS AND NOTES ALONG HIGHWAY 49 BOWEN AND CRIPPEN 



83 



in 1864 culminated a steady decline which had begun some years earlier. 

 A good dirt road from the Alleghany mining district joins Highway 49 

 in the vicinity of Goodyears Bar. 



Three-tenths of a mile east of Goodyears Bar is a prominent out- 

 cropping of serpentine which is associated with fine-grained dark intru- 

 sive rocks. Half a mile east of the serpentine belt is a small area of meta- 

 gabbro. The fine-grained basic rocks are cut by quartz veins. 



A broad zone of faulting and deformation is visible along the high- 

 way 1.4 miles west of Downieville. The meta-volcanics there are much 

 contorted and, in many places, are impregnated with pyrite. In the 

 stream bed below, deep circular depressions known as potholes or kettles 

 may be seen in the exposed bedrock. Potholes are formed by the eddying, 

 spinning action of rapid water over uneven, bare rock. Gravel and 

 pebbles caught in the depressions are spun by the currents and aid in 

 the circular downcutting effect. They are a common feature along streams 

 of considerable gradient. 



Downieville, county seat of Sierra County, is situated at the junc- 

 tion of the north and east branches of the North Fork of the Yuba River. 

 Lofty tree-covered mountains surround it on all sides and it is a fitting 



location for the center of a well named county. There is very little flat 

 land in the county and this is located either along river bottoms or on 

 upland remnants of the Eocene surface. Like Goodyears Bar, Downie- 

 ville was found in 1849 by a party of gold seekers. Originally known 

 as The Forks, the name was changed to Downieville in honor of William 

 Downie, one of the initial settlers. More than 5000 people jammed the 

 town in 1851 and some rich strikes were made. So determined were the 

 miners to get the gold from the bed of the Yuba that they flumed and 

 diverted the river from its bed between Downieville and Goodyears Bar. 

 This worked beautifully as long as summer held out, but winter floods 

 quickly wiped out the project. After the placer mines were exhausted, 

 gold mining went on in hydraulic, drift and a few lode mines. The town 

 is now supported by lumber and mining interests and by Forest Service 

 men. Very few historical buildings remain, the County Courthouse and 

 St. Charles Hotel having burned in 1947. The Pioneer Museum, a well- 

 built stone building with iron doors and window shutters, was restored 

 by the heirs of pioneer J. M. B. Meroux and dedicated to the Pioneers 

 of Sierra County by the Native Sons and Daughters of the Golden West 

 in 1932. Costa 's grocery store, also of stone, dates from 1852. 







FIG. 41. I'enn copper-zinc mine near Campo Seco, 

 Calnveras County. Photo by C. V. Averill. 



FIG. 42. Stamp mill near Jamestown, Tuolumne County, 

 used for conrentriitiiiB chrome ore. Photo by C. T. Arerill. 



