105 



VEGETATION OF THE SUMMIT OF MT. ST. HELENA. 



By Willis L. Jepson. 



The mountain mass of Mt. St. Helena is exceeded in height by 

 no point in the Coast Ranges between Clear Lake and the Peak of 

 San Carlos, saving only Mt. Hamilton. Its highest point is 4,343 

 feet above sea level, or exactly one hundred feet less than that of 

 the mountain last named. It is the culminating point of the middle 

 Coast Range, locally known as the Mayacamas Mountains, a range 

 of north and south trend, which secludes the Clear Lake region on 

 its east and extends southward to the Carquinez Straits (connecting 

 the bays of San Pablo and Suisun), where it becomes low and 

 barren and is known as the Benicia Hills. A branch of the Russian 

 River originates on the western side of Mt. St. Helena, and, joining 

 the main stream, its waters, running in a westwardly direction, 

 reach the Pacific Ocean. Another stream, Putah Creek, the Rio 

 de los Putos of the Spanish Californians, has its beginnings in the 

 canons on the eastern slope of the mountain, and this winds east- 

 ward for some seventy or eighty miles, cutting straight through the 

 bold western face of the Inner Coast Range and eventually joining 

 the Sacramento River. 



Notwithstanding its height this mountain is not easily distin- 

 guished at a distance, by reason of being flanked by prominent 

 ridges, but its regularly-sloping notched summit and abrupt sides 

 continually engage the attention and interest of the traveler journey- 

 ing through the broken Coast Range country north of the bay of 

 San Francisco. 



From whatever mountain -ridge or favored valley one may have 

 the advantage of view, its outline against the sky is almost as 

 constant as is that of a conical peak. This is due to the 

 subquadrilateral arrangement of the prominent shoulders of the 

 mountain. The summit is made up of three main ridges. The 

 first of these lies in a northeasterly and southwesterly direction, and 

 is composed of two rounded knobs connected by a low divide. The 



Contributions from the Botanical Laboratories of the University of 

 California, No. 6. 



