CHOEOGRAPnT. 13 



The most notable of these are the Alviso or Guadalupe slough, 

 at the head of San Francisco Bay ; the San Antonio slongh, 

 opposite San Francisco city ; the Petaluma, Sonoma, and Napa 

 sloughs, opening into San Pablo Bay; and Suisun and Pacheco 

 sloughs, opening into Suisun Bay. 



§ 11. Tide-Land. — Along the borders of these bays, and of 

 the Tulare and Kern Lakes, and of the Sacramento and San 

 Joaquin Rivers, there are extensive tracts of swamp-lands, usu- 

 ally called "tule-lands," from the tule^ a species of rush which 

 grows on them. Nearly all the tule-land west of Sacramento 

 and Stockton, to which points the tides extend, are salt marsh- 

 es ; but north of Sacramento, and south of Stockton, the tule- 

 lands are fresh-water swamps. The extent of this marshy land 

 varies in different seasons ; but at my estimate, there are eighty 

 square miles on the borders of San Francisco Bay, eighty on 

 San Pablo Bay, sixty on Suisun Bay, two hundred on the Sac- 

 ramento River, one hundred on the San Joaquin, two hundred 

 on the Tulare Lake, and the slough leading from it, and one 

 hundred and twenty south of Tulare Lake — making eight 

 hundred and forty square miles in all. 



§ 12. Bierra Nevada. — The Sierra Nevada is four hundred 

 and fifty miles long (in California) and seventy wide, with a 

 height varying from five thousand to eight thousand feet above 

 the sea-level. Nearly its whole width is occupied with its 

 western slope, which descends to a level of three hundred feet 

 above the ocean ; whereas the slope on the eastern side is only 

 five or six miles wide, and terminates in the Great Basin, which 

 is itself from four thousand to five thousand feet above the sea. 

 Nearly all the snows and rains that visit the Sierra Nevada fall 

 on its western slope, which has all the large rivers. These 

 rivers run westward, at right angles to the course of the chain, 

 and cut it into steep hills and deep ravines, canons, and chasms. 

 The valleys are all small, and it is rare to see a hundred acres 

 of level, tillable land, even on the banks of the largest moun- 

 tain-streams. The greater pnrt of the Sierra Nevada is cov- 

 ered with timber. The oak, manzanita, and nut-pine, grow to 



