surgeons' reports — CALIFORNIA — NORTHERN DISTRICT. 479 



to the eastern line of the State; thence northward to the Oregon line, embracing an extent of 

 country of some three hunclreil miles in length and two hundred and fifty miles in breadth, lying 

 between the parallels of 37° 30' and 42° north latitude. It is composed of the following Counties, 

 viz: Butte, Colusi, Del Norte, Klamatb, Lake, Lassen, Mendocino, Marin, Napa, Plumas, Sutter, 

 SUasta, Siskiyou, Solano, Sonoma, Sierra, Trinity, Tehama, Yuba, and Yolo. The relative geo- 

 graphical position of the above-named counties is as follows, commencing on the bay of San Fran 

 Cisco on the south, thence north, skirting the coast to the Oregon line: 1st, Marin ; 2d, Sonoma; 

 3d, Mendocino; 4th, Humboldt; 5tb, Klamath ; Gth, Del Norte. Second tier of counties, lying west 

 of the Sacramento Eiver and occupying the eastern slope of the Coast range of mountains, com- 

 mencing at Suisun Bay on the south, thence north to the Oregon line : 1st, Solano ; 2d, Napa ; 3d, 

 Lake; 4th, Yolo; 5th, Colusi ; Gth, a part of Tehama, Trinity, and a part of Siskiyou. Third tier 

 of counties lying in the valley of the Sacramento, and occupying the western slope of the Sierra 

 Nevada range of mountains, commencing at the southern line or boundary of Sutter County: 

 First. Those counties lying mostly in the valley: 1st, Sutter; 2d, Yuba; 3d, Butte; 4th, Tehama. 

 Second. Those counties lying mostly in the mountains: 1st, Sierra; 2d, Plumas; 3d, Lassen; 4th, 

 Shasta; 5th, Siskiyou. » # * 



What is known as the Coast range of mountains passes througli the whole extent of the dis- 

 trict from south to north. Between it and the Sierra Nevada range lies the great Sacramento 

 Valley, with its rivers, lakes, and tulares. The Sacramento River drains the eastern slope of the 

 Coast range and the western slope of the Sierra Nevada. 



The western aspect of the Coast range is abrupt and extremely broken. The streams for the 

 most part pass through narrow defiles opening into small but fertile valleys. The mountain sides, 

 though generally precipitous, contain much sloping prairie ground, which produces a luxurious 

 growth of grass, nearly to their summits. 



An abundance of fine timber is also found on the broken table-grounds near the coasts, in the 

 valleys, and on the mountain sides. The forests of this region beggar all description. When in 

 the midst of one the traveler is lost in amazement, and can scarce believe what his eyes behold. 

 Trees are seen towering to the height of three and four hundred feet, their diameters varying from 

 twelve to thirty feet; they are scattered at short intervals over many acres, giving an idea of 

 weight sufficient to crush in the crust of earth upon which they stand. 



In the bosom of the Coast range lies Clear Lake, at an elevation of three thousand five hun- 

 dred feet above the level of the ocean. From the bed of this lake has been obtained a very pure 

 article of borate of soda. In this vicinity are also found the famous Pacific geysers, which are 

 continually active, spouting forth jets of steam and boiling-waler to the height of many feet. Sul- 

 phur and iron si)rings of all temperatures are also found at many points in this range. . Gold, silver, 

 coppei', platiuuu), and iridium are products of this region, the two latter metals being found on the 

 beach, associated with fine gold and black sand. Recently, coal and petroleum have been added 

 to the foregoing list. 



The eastern declivitj', like the western, is abrupt and broken, and quickly slides off into foot- 

 hills which are chopped into hundreds of spurs and low ridges extending quite into the plains. 

 The eastern slope of the Sierra Nevada is more gradual; but, here too, is exhibited the general 

 characteristic of all mountain ranges on the Pacific ; abrupt declivities, deep calions, and broken 

 surfaces. As the valley is approached the foot-hills slide out, as it were, from the mother range in 

 almost endless number. These lower ranges are composed of drift and obtrusive rocks. On the 

 surface, for a few feet in depth, may be found clay, loam or sand, then a crust termed bedrock, 

 and underneath an indefinite series of strata of sand, gravel, bneccia, granite, cement, &c. It is in 

 these strata that placer gold is found; the richest deposits are found in a stratum of course gravel 

 resting upon the bed-rock. 



I may here observe that, contrary to what usually occurs in mountain ranges, both declivities 

 of the Coast range are steep, as is also that side of the Sierra Nevada facing the valley. The reason 

 probably is, that the foothills of both have at some period been washed by tidewater, when the 

 Sacramento Valley was the bed of a continuous bay, and the Coast range of mountains formed the 

 sea boundary from the present bay of San Francisco northward. 



