The water areas of the Dakotas and Montana 

 include the upper Missouri river system with its large 

 water impoundments, and many water storage reser- 

 voirs. Utah has 20 percent of this section's water, 

 concentrated mostly in the Great Salt Lake. 



In addition to the major river systems flowing from 

 the Rocky Mountains — the Missouri and Snake in 

 the Northern Rockies, and the Colorado — this 

 mountainous area has many small lakes and streams. 

 Arizona, Utah, and Nevada have minimal amounts of 

 these small waters. 



Although the inland water areas in the Rocky 

 Mountains and Great Plains are relatively small, they 

 are of great importance. They support fish and wild- 

 life and are the focal points for many outdoor recrea- 

 tional activities. They also provide most of the water 

 for domestic use and for the irrigation of much of the 

 cropland and improved pasture in the more arid parts 

 of the section. 



The Pacific Coast 



This section includes five States: California, 

 Oregon, Washington, Alaska, and Hawaii. The range 

 of environmental conditions within the region is 

 extreme. 



The coastal areas of Southeast Alaska, Washing- 

 ton, Oregon, and Northern California are character- 

 ized by a maritime climate with ample precipitation 

 and small ranges in annual temperature. Precipita- 

 tion ranges from 30-150 inches or more and is well 

 distributed throughout the year. Temperatures are 

 cool and produce a very damp, humid climate with 

 much cloud cover. This area has many steep, rugged 

 mountains fronted in places by narrow coastal plains. 

 The interior mountains rise to 8,000 feet or more. 

 Much of the area has been glaciated, particularly in 

 the northern portion. Soils are strongly leached and 

 acid and have thick surface organic layers. They are 

 highly productive for coniferous forests. 



In contrast, the eastern portions of Oregon and 

 Washington, and northeastern California are similar 

 to the more semi-arid Rocky Mountain region. This 

 area is a relatively dry upland with occasional moun- 

 tain uplifts, and is dissected by the Columbia River 

 and its major tributaries. Soils are very productive 

 where water is available. 



Most of California is dominated by a Mediterra- 

 nean climate with distinct wet and dry seasons. Pre- 

 cipitation falls mainly in the winter months and 

 summers are hot and dry. Physiography ranges from 

 the flat central valley to the steep, low mountains on 

 the coast and the high, rugged Sierra Nevada in the 

 interior. Soils are extremely variable. 



The northern and western coastal plains of Alaska 

 are dominated by an arctic climate with short cool 

 summers and long, extremely severe winters. Precipi- 

 tation is light, often less than 10 inches. Broad, level 

 plains and low, rolling foothills occupy the area. The 

 tundra soil sare wet and cold, and underlain by sand, 

 gravel, and marine sediments. Most soils have a thick 

 permafrost layer. 



Interior Alaska is characterized by a subarctic cH- 

 mate and the steep, rugged Brooks and Alaska 

 Mountain ranges. Broad valleys, dissected uplands, 

 and lowland basins occur between the mountain 

 ranges. Soils are strongly leached and have severe 

 climatic limitations. Permafrost is common. 



The islands of Hawaii have a tropical climate and 

 are hilly and mountainous. The islands have a com- 

 plex pattern of leached soils, rocky highlands, and 

 coastlines. 



Forest Land 



Forests cover 93 million acres, or 46 percent, of the 

 land in the lower Pacific Coast States — CaHfornia, 

 Oregon, and Washington (table 2.1). The forests in 

 these States are known throughout the world for their 

 large trees. Less well known, but of great importance 

 to resource managers, is the extreme variability in 

 productivity and composition of the forest. 



The lower Pacific Coast States' forest ecosystems 

 fall into two forest subregions — the humid coastal 

 area, and the arid eastern or interior area. 



The coastal subregion — western Washington and 

 Oregon, and northwestern California — has three 

 major forest types, redwood, Douglas-fir. and 

 hemlock-sitka spruce. The forests in this subregion of 

 heavy rainfall and mild winters are among the most 

 productive in the world. Biomass accumulations in 

 the redwood and Douglas-fir ecosystems exceed 

 those reported for any other ecosystem.' 



The redwood ecosystem of the California Coast 

 totals only about 800,000 acres, but is important as a 

 timber producing region, scenic wonder, and recre- 

 ational resource far out of proportion to its limited 

 acreage (table 2.9). Douglas-fir is the major conifer 

 associate throughout the ecosystem, although west- 

 ern hemlock, grand fir, and western redcedar are 

 locally important. Tanoak and Pacific madrone are 

 common hardwood associates throughout most of 

 this ecosystem. 



The Douglas-fir ecosystem, which totals 21 million 

 acres, is the largest and most important in terms of 



** Franklin, J. F., and C. T. Dryness. Natural vegetation of 

 Oregon and Washington. U.S. Department of Agriculture, For. 

 Serv. Gen. Tech. Rep. PNW-8. 1973. 



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