THE MAMMALS OF MOUNT MAZAMA. 
207 
The whole mountain, except a small pumice desert north of the Lake 
and some narrow meadows on its rim, is covered with a dense forest, 
notable for the size and magnificence of its trees. This forest is 
made up of a number of species of conifers, arranged in definite belts 
or zones, corresponding with the three faunal zones — the Hudsonian, 
Canadian, and Transition — into which the life of the mountain slopes 
may be divided. 
The lower part of Klamath basin, including the treeless area 
between Klamath Lake and Tule or Modoc Lake, and a strip on the 
east side of Klamath Lake south of Williamson river, belongs to the 
Upper Sonoran Zone, and is characterized by such mammals as the 
Black-tailed Jack Rabbits, Kangaroo Rats, Pocket Mice, Grasshopper 
Mice and other interesting forms which do not occur at Fort 
Klamath or on the mountain, and consequently are not mentioned 
in the accompany list. ' 
The life zones of Mount Mazama, beginning at the bottom, 
may be characterized and defined as follows: 
(1) The Transition Zone. — The Transition Zone covers the 
flat between Upper Klamath Lake and the base of Mount Mazama 
(thus including the ground formerly occupied by Fort Klamath), 
and pushes up the south slope to an altitude of about 1,525 meters 
(5,000 feet), which point is 10 or 12 miles northwest of the old Fort. 
To the south, it reaches continuously to Williamson river, and 
covers the hills beyond to within a mile or two of the town of 
Klamath Falls. To the west, it is believed to extend continuously 
from the Klamath Lakes to the lower Rogue river valley in south- 
western Oregon and Klamath valley in northwestern California. 
The characteristic and dominant tree of the Transition Zone is 
the Yellow Pine {Pinus ponderosa) which grows to very large size — 
single trees measuring upwards of 7 feet in diameter — and covers 
nearly the whole of the plain north of Williamson river and the 
south slope of the mountain up to the altitude mentioned. Scattered 
through this splendid forest are trees of the Incense Cedar {Li- 
bocedrus decurrens) and the long- coned Sugar Pine {Pinus lamber- 
tiana). The White Fir (Abies concolor), Douglas Spruce {Pseudo- 
tsuga mucronata)^ and Aspen (Populus tremuloides) also occur here 
