12 



various sizes, formiug the "mountain meadows" for wLicb this region 

 is justly famous. The valleys of many of the larger mountain streams, 

 uniting with those of their more important tributaries, often form areas 

 of considerable extent, in which, because of the rich soil and abundant 

 supply of moisture, luxuriant growths of native grasses are produced. 

 These areas, variously called "basins,'' "parks," etc., protected as they 

 are by mountains on all sides and provided with an abundance of 

 excellent forage and pure water, are magnificent natural pastures, 

 whose only drawback is that often the altitude is so high and the snow- 

 fall is so great that they can be used for only a limited portion of the 

 year. (See fig. 2.) Excellent examples of these areas are Spanish Creek 

 basin, in southern Montana ; Centennial Valley, at the head of the Little 

 Laramie liiver, in Wyoming, and the numerous "parks" of Colorado. 



Fig. 2. — The ideal summer range. (From pbutograiili by I'rof. A. Nclsnii.) 



In some of the outlying ranges the mountains are less rugged, the 

 sloi)es are often but sparsely or not at all wooded, and hence otter pro- 

 portionately larger forage producing areas. For example, the Big 

 ITorn and Bear Lodge ranges, in Wyoming, contain large areas of grass 

 lands, the former exi)anding towaid tlie south into a broad, irregular 

 plateau, a very considerable portion of which is covered with a fine 

 sod of native grasses. In many iwrtions of this region the mountains 

 are fringed with an irregular series of foothills, which iiass sometimes 

 abru])tly, sometimes gradually, into table-lands or mesas, and these in 

 turn are followed b}^ broad valleys and open prairies or plains proi)er. 

 The freciuent arrangement of the land along streams into terraces or 

 successive '-benches" is of considerable importance from an agricul- 

 tural point (»f view, since very often the table-lands (lifter considerably 

 from the valleys below as to the supply of moisture and the earliness 

 and length of the growing season. This is well illustrated by the 

 Gallatin Valley about Bozeman, Mont., where the season is much 



