THE MAMMALS OF MOUNT MAZAMA. 
211 
(Microtus arvicoloides), Liie alpine FhenHCoinys oropbilus, the 
Mount Mazama Red-backed Mouse (Evotomys mazama)^ Baird's 
Alpine Vole {Microtus bairdi) and the Sierra Pika, or Little Chief 
Hare {Ochotona schisticeps). The Sierra Sewellel {Aplodontia 
major) occurs locally. A number of other species which are more 
or less common on top of the mountain, range down through the 
Canadian Zone, under which head they have already been enumerated. 
The boundaries between the zones are marked by belts of over- 
lapping, where the trees of the zone below mix with those of the 
zone above over a belt covering a vertical difference in altitude o^ 
about 125 meters. The actual breadth varies according to the slope, 
being less than a quarter of a mile on very steep slopes and a mile or 
more on gradual slopes. 
The Yellow Pine forest of the Transition plain between the 
north end of Klamath Lake and the south base of the mountain is 
interrupted in a number of places by trees which come down from 
the Canadian belt above. These trees are chiefly Lodgepole Pines, 
more or less mixed with Douglas Spruces and White Firs. It will 
be observed that they follow the cold streams and cover the flat 
swampy lands where the temperature is much lower than in the 
pine forest. Birds and mammals of the Canadian Zone inhabit these 
places as will be shown later. 
THE FORT KLAMATH PLAIN.— The site of Fort Klamath, 
now abandoned, will always be a place of special interest to natural- 
ists, on account of the large collections in different branches of 
natural history made there by Captain (afterwards Major) Charles E. 
Bendire and Dr. J. C. Merrill.* It is moreover the type locality of 
a number of species, for which reason its faunal relations should be 
clearly understood. From the preceding description, it will be 
evident that while the post itself is in the Transition Zone, a day's 
ride to the south enables the collector to obtain Upper Sonoran 
species, and a day's ride to the north or west takes him into the 
mountains where he is surrounded by Canadian and Hudsonian 
species. 
*A very full and valuable list of the Birds of Fort Klamath, with critical notes by William 
Brewster, was published in the Auk for 1888 by Dr. J. C. Merrill. An earlier and less complete list 
had been published by Dr. E. A. Mearns. 
