12 STOCK RANGES OF NORTHWESTERN CALIFORNIA. 



bench between the shore line and the summit of the first mountain 

 ridge, which is about 1,600 feet high. This ridge marks the western 

 edge of the redwood belt. For the most part this belt is elevated some 

 5.0 or more feet above the sea, but at Humboldt Brj and Crescent City 

 it has been eroded almost to sea level, there forming a large and very 

 fertile flood plain. It is subject to heavy summer fogs, enjoys a more 

 equable summer climate and a greater amount of moisture than is 

 found in the interior, and is relatively cool. The soil is considered 

 poor except at a few points ; it is light, being abundantly charged 

 with drift sand. 



3. The Redwood Belt, lying between and parallel with the coast 

 bluff belt and the interior plateau, and consisting of rough ridges, 

 separated by narrow V-shaped canyons. It is covered by a more or 

 less dense growth of redwood (Sequoia sempervirens) , and is a cli- 

 matic and phytological rather than a geographical area, embracing 

 and being limited to the redwood forest. It runs almost the whole 

 length of the coast of northwestern California, apparently being inter- 

 rupted in only one or two places, and lies for the most part away from 

 the coast line, sheltered from cool and violent winds behind a ridge 

 which runs nearly parallel with the shore. Scattered redwood trees 

 are but rarely found outside of this belt, which comprises the forest 

 proper. The heavy summer sea fogs, drifting high overhead across 

 the narrow bench of bluff land, are intercepted in their course by the 

 trees on the summits of the ridges, or, when they lie low, roll along 

 the broad river valleys and more numerous narrow canyons opening 

 into the redwood forest, saturating the tree tops, and by their means 

 also the soil below, with abundant moisture. The actual conditions 

 which delimit this redwood belt are not at present clearh' understood, 

 but climate appears to have been, above an}' other evident physical 

 cause, a potent factor in the development of the forest. The soil con- 

 ditions appear to be generally comparable to those of the plateau can- 

 yons, except for the additional amount of humus due to the presence 

 of the trees. 



1. The headwaters of the Russian River, forming a connecting link 

 between the distinct topographical region of northwestern and that of 

 western middle California, otherwise called the San Francisco Bay 

 region, to the latter of wiiich it strictly belongs. It is included in this 

 report because it lies within Mendocino County and because it AYas the 

 starting point of the expedition. 



5. The drainage basin of Clear Lake, for the most part a stony 

 and mountainous region, walled in on all sides, and with little level 

 land. Its resources are mainly pastoral, though the lake is fringed 

 by some rich farming and fruit land. 



6. Trinity County, an isolated mining region, almost willed in by 

 high mountains, and including the headwaters of Trinity River. 

 Scarce!}' am'thing is known of the botanj' of this very distinct topo- 



