10 American Midland Naturalist Monograph No. 4 



about 3,100 feet at Belton on the southwest to 10,438 feet at the top of Mt. 

 Cleveland. Rainfall averages 27 inches at lower elevations on the west side 

 but is slightly less on the east side of the Continental Divide, the yearly 

 rainfall being recorded as 22 inches at Glacier Park Station. 



The vegetation cover is interesting and varied. Forests on the east side 

 of the Divide are typical of those of the Rocky Mountain region in general, 

 while in some areas on the west side they are more characteristic of the 

 Pacific Northwest. 



In the lower valleys on the west side of the park, such as in McDonald 

 Valley, there are found species similar to those in the lowland forests of 

 Mount Rainier and Olympic National Parks, such as western red cedar 

 {Thuja plicata), western hemlock (Tsuga heterophylla) , and occasionally 

 lowland white fir (Abies gratidis) . Douglas fir (Pseudotsuga taxijolia) , 

 western larch (Larix occdentalis), western white pine (Pinus monticola), and 

 Engelmann spruce (Picea Engelmanni) are common associates. 



Lodgepole pine (Pinus contorta) covers extensive areas, forming dense 

 stands at low and middle elevations over much of the park, or in association 

 with alpine fir (Abies lasiocarpa) and Engelmann spruce. Shrub species 

 found commonly in openings in the lower forests up to about 4,500 feet or 

 sometimes higher, include the following: serviceberry (Amelanch.er alnifolia), 

 western thimbleberry (Rubus parviflorus) , red raspberry (Rubus idaeus var. 

 aculeatissimus) , common snowberry (Symphoricarpos albus), shinyleaf spi- 

 raea (Spiraea lucida) , big whortleberry (Vacc.nium membranaceum) , west- 

 ern yew (Taxus brevijolia) , creeping hollygrape (Berberis repens), bearberry 

 (Arctostaphylos uva-ursi), red-osier dogwood (Corniis stolonifera) , bunch- 

 berry dogwood (Corniis canadensis), mountain maple (Acer glabrum), wild 

 tose (Rosa species), black chokecherry (Prunus virginiana var. melanocarpa), 

 prickly currant (Ribes lacustre), and creambush rockspiraea (Holodiscus dis- 

 color) . 



At higher elevations, up to about 6,000 feet, in addition to many of the 

 above-mentioned species which extend into the higher zone, common shrubs 

 are bearberry honeysuckle (Lonicera involucrata) , Utah honeysuckle (Loni- 

 cera utahensis) , rusty menziesia (Menziesia jerruginea) , subalpine spiraea 

 (Spiraea densiflora), mountain ash (Sorbus scopulina), and black bead 

 elder (Sambucus melanocarpa) . 



Subalpine meadows are dotted with islands of alpine fir and Engelmann 

 spruce. Whitebark pine is common just below timberline on both sides of 

 the Divide, and Alpine larch (Larix Lyall.) is found in some places. Shrubby 

 species occurring here and in alpine meadows include red mountainheath 

 (Phyllodoce empetriformis) , mountain bog kalmia (Kalmia polifola var. 

 microphylla) , and low alpine willows. 



Yellowstone National Park 



■ '''cl'owstonc National Park in northwestern Wyoming is essentially a 

 high plateau which lies mostly between 7,000 and 8,500 feet elevation, al- 

 though the terrain descends to 5,400 feet in the lower valleys. From the 



