56 



GEOLOGIC GUIDEBOOK ALONG HIGHWAY 49 



[Bull. 141 



via shaft and winze. The veins are faulted off on the south side of town 

 and attempts to relocate the ore shoots south of the cross-fault have 

 failed. The working shaft and adjacent stopes are located on the north 

 side of town in an area now set aside as a city park. The depressed portion 

 of the park is the result of the caving of the stopes beneath. 



A half mile west of the Utica is the Gold Cliff mine, which was oper- 

 ated by the Utica Mining Company for about five years after the Utica 

 closed down. The Gold Cliff is also a consolidation of half a dozen early- 

 day claims. It is on the main Mother Lode fault system whereas the Utica 

 is probably on the same east spur as are the Carson Hill ore bodies. The 

 Gold Cliff was prospected to a depth of 2700 feet along an incline which 

 averaged 45 in dip, but most of the ore came from above the 1900 foot 

 level. Between the 1600 and 1700 foot levels, the ore bodies are offset 

 to the north by a nearly horizontal fault of several hundred feet displace- 

 ment. The Utica Mining Company announced a total production for the 

 Gold Cliff of $2,834,000. 



ALTAVILLE TO MOKELUMNE HILL MAP 4 



Altaville, located at the junction of Highways 49 and 4 one mile 

 north of Angels Camp is, like its larger neighbor a modern town with but 

 few remaining historical spots. Originally known as Cherokee Flat, Alta- 

 ville was a crossroads point of supply for adjacent placer mines. A group 

 of drift mines which has produced much placer gold is located to the 

 east of Altaville and Angels Camp. The term drift mines is here applied 

 to underground placer mines which reach the old buried river gravels by 

 shafts and tunnels. The Calaveras Central, Slab Ranch, Golden River, 

 and Vallecito Western are some of the mines located in this region, all 

 of which entered the Central Hill gravel channel at different places on 

 its course. This fossil stream channel lies buried about three hundred 

 feet beneath the surface and is filled with gravel and volcanic ash. The 

 Calaveras Central mine was being rehabilitated early in 1948, but is now 

 closed. Its workings are very extensive and reach the buried channel on 

 a bend in its course from west to north. Coarse gold nuggets were found 

 directly on bedrock slate riffles where the Eocene gutters cut across and 

 followed the structure. Huge boulders lie on the upturned edges of the 

 slate. Rhyolitic lake bed ash containing fossil leaves lies upon this coarse 

 gravel. Above this and filled to the surface is volcanic ash and stream 

 gravel of all sorts. 



These mines are located between Highway 4, running east from 

 Angels Camp, and the Murphys Grade road which runs east from Alta- 

 ville. The sidetrip from Altaville to Murphys and back to Angels Camp 

 is one which no visitor to this part of the gold country should miss. 



Traveling east from Altaville the quarried outcrops of grayish-tan 

 rhyolite tuff of the Valley Springs formation can be seen in rounded 

 hills above a surface of lesser relief. The tuff overlies the gravel channels 



in many planes and it is beneath this material that the drift mines have 

 been driven. The tuff has been extensively quarried for use as a building 

 stone because of its accessibility, durability, and workable properties. 

 The Calaveras Central mine is located on the north side of Bald Hill the 

 turnoff to which is six-tenths of a mile east of Altaville. As seen from the 

 south, the name Bald Hill is a misnomer, that side of the hill being 

 brushed over. Bald Hill is the site of the famous "Calaveras Skull" 

 hoax, perpetrated on geologist J. C. Whitney and others in the 1860 's, 

 in which an Indian skull was placed as a practical joke at the bottom of 

 a shaft which was sunk in the Tertiary stream gravels. A few miles 

 beyond Bald Hill the road locally known as Murphys Grade begins a 

 gradual ascent up the park-like canyon of Angels Creek to Murphys, 

 probably the best preserved and most beautiful of the old towns which 

 date from the gold rush. Very little modernization has been done there. 

 Looking down its main street with its fine old buildings and overhanging 

 trees is like turning back the pages of history nearly a hundred years. 

 Murphys is the starting place for Mercers Cave, a limestone cavern 

 privately owned but open to the public, the Sheep Ranch mining district, 

 Murphys mining district, and the High Sierra of Ebbetts Pass. 



The lode mines of the Murphys district, located on Highway 4 a few 

 miles northeast of the town of Murphys, differ from most other gold 

 deposits in the vicinity of the Mother Lode in that the veinlets or 

 stringers are in limestone country rock instead of in meta-volcanies or 

 meta-clastics. The mines were discovered in 1848 but were never sensa- 

 tional producers. 



Doubling back on Highway 4 toward Angels Camp, the hydraulic 

 diggings of Douglas Flat are evident to the northwest of the road. This 

 is one of the most southerly of a great series of immense hydraulic 

 diggings which are scattered from Calaveras to southern Plumas County. 

 Above the face of the Douglas Flat pit is a black lava-breccia cap the 

 edges of which are fluted by weathering, but have the false appearance 

 of columns, jointing which is characteristic of the solid lava of Table 

 Mountain latite. The latite flow is located to the east. 



Vallecito is two and a half miles southwest of Douglas Flat. At the 

 town of Vallecito a road from Columbia joins Highway 4. This road starts 

 north from Columbia, following the Eocene Columbia River channel, 

 passing close to a large marble quarry in Calaveras limestone to the 

 east, and then descending the deep and spectacular canyon of the Stanis- 

 laus River. On the way one may look up this magnificant canyon and 

 see clearly where the river has cut through a wide belt of Calaveras 

 limestone. Table Mountain latite shows up prominently on the north side 

 of the canyon as well as the south, and as the road winds down through 

 granite rock various fine scenes come into view until finally it crosses 

 the river at Parrott Ferry. Here one should examine the outcrop of 

 granitic rock with inclusions of earlier intruded rock bodies and thou 



