FLORA OF THE CASCAT3ES 
143 
FLORA OF THE EAST SLOPE OF THE CASCADE 
MOUNTAINS, IN CROOK COUNTY, OREGON. 
MORTON E. PECK. 
Ill the latter part of June; 1914,, the writer joined a company 
of biological investigators and collectors, ivorking under the 
general direction of Mr. yeriion Bailey, field naturalist of the 
U. S. Biological Survey, on a trip across the .Cascade mountains, 
by way of the McKenzie Pass. The purpose of the expedition 
was to secure certain zoological and botanical data and speci- 
mens of the animal and plant life of the region, with a view to 
determining the life zones of this section of Oregon, as well as 
to add material to the collections of the several institutions 
represented by the members of the party. 
The McKenzie Pass crosses the Cascades nearly due east of 
Eugene, where McKenzie river enters the Willamette. Eugene 
is not far from the center of the state north and south, and 
about fifty miles from the coast, 
We left Eugene on June 27, and traveled by stage up the 
valley of the McKenzie for fifty miles, to McKenjzie Bridge, 
where we remained for some time. The last third of this dis- 
tance led through the heavy coniferous forest characteristic of 
the western slope of the Cascades. Much of this has now been 
cut off. 
It may be well, for the sake of comparison, to touch upon 
some of the main features of the fiora of the western slope and 
the summit before considering that of the eastern slope, in order 
to bring out more clearly the remarkable contrast due to the 
difference in precipitation. 
The elevation at McKenzie Bridge is about 500 meters, the 
annual precipitation 1743 mm., a considerable part of which is 
snow. The flora is almost typically Transition, resembling in 
the main that of the Willamette Valley, but the presence of 
such species as Thuja pUcata, Tsuga heterophylla, Echinopanax 
horridum, Pyrola hracteata, Arctostaphylos . tomentosa, Gaul- 
theria shallon, and several others, give it something of the Humid 
Transition or coastal slope character, TherC; is also an admix- 
