270 Description of port of Wyominr) Territory. 



tlie snows disappear with the approach and advance of summer. The 

 country for the most part is treeless and destitute even of large shrubs, 

 excepting along some of the water courses. The principal streams are 

 fringed with trees, consisting of cotton wood and willow, and the val- 

 leys through which they run produce mostly rushes and sedges, with 

 some coarse grasses, as Elymus condensatus and Triticum repcns. Hol- 

 lows of the hills and narrow valleys, favorable to the retention of mois- 

 ture, support forests of small aspens. The higher terraces and foot 

 hills approaching the mountain ranges are covered with dense forests 

 of aspens, pines, and firs, with a rich undergrowth of herbaceous 

 plants. The great mountains themselves present a broad belt of pines 

 and firs, from which project the rocky summits as bare of vegetation 

 as the wide plains at their base. Many of the lower hill sides and hol- 

 lows in certain situations are sparsely covered with cedars, most of 

 which are very old in appearance, and remarkably distorted, twisted 

 and broken. 



The principal growth of the plains consists of sage bushes, curiously 

 distorted and split, so as to remind one of the cedars just mentioned. 

 In some places the sage bushes are mingled with or replaced by t!ie 

 grease wood (sarcobatus vermiculatus) . Wide, bare, path-like intervals 

 surround the bushes, or the spaces are occupied by scanty grass, which 

 formerly furnished food to the buffalo, now become extinct in this 

 region and elsewhere west of the Rocky Mountains. 



The fossils for the most part are derived from the more superficial 

 deposits of the great Uintah basin, which Prof. Hayden has distin- 

 guished as the Bridger group of beds. These compose the terraces or 

 table lands in the neighborhood of Fort Bridger, and consist of nearly 

 horizontal strata of variously colored, indurated clays and sandstones. 

 As the beds wear away, through atmospheric agencies, on the naked 

 declivities of the flat-topped hills, the fossils become exposed to view, 

 and tumble down to the base of the hills, among the crumbling debris 

 of the beds. 



The flat-topped hijls or terraces of the Bridger basin, rising from 

 broad valleys and extended plains, form the most conspicuous objects 

 of the landscape. A similar condition of the country, alternating 

 with boundless plains and great mountain heights, forms a character- 

 istic feature of a great part of the region west of the Mississippi. 



The flat-topped hills, table-lands, bench-lands, or terraces, as they 

 are variously named, seen from lower levels, are usually called 

 " buttes," especially when they are of limited extent. The name is of 

 French origin, and signifies a bank of earth or rising ground. The 

 name is likewise applied in a more restricted sense, to the prominent 



