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NATURALIST'S GUIDE TO THE AMERICAS 



homa City via Geary, and drive 5 mi. or 

 more (a). 



9. Black Mesa. Go to tGuymon 

 (population 1507), in "Panhandle," on 

 the Chicago, Rock Island and Pacific 

 R. R., and then (a) overland nearly 103 

 mi. northwest If. — H. H. L. 



10. Arbuckle Mountains. (B3.) 860 

 sq. mi., 550,003 acres. A much dissected 

 plateau, showins; striking effects of 

 erosion; a pre-Cambrian granite core 

 surrounded by the later formations in 

 series at various angles; prairie ridges 

 and timbered valleys; clear, Tapid- 

 flowing streams, with many beautiful 

 waterfalls and springs, travertine de- 

 posited by algae; artesian wells and 

 springs, charged with minerals. Eleva- 

 tion, 750 to 1350 ft. Arbuckle, Murray 



County, Santa Fe R. R. — Chas. 0. 

 Chambers. 



A rendezvous and camp-ground of 

 many geological students from the 

 State University and elsewhere. 



11. Kiamichi Mountains. (B3.) In 

 Leflore County. About 100 sq. mi. or 

 64,000 acres, of rugged hills or mountains 

 in the Ouachitas. Deciduous and conif- 

 erous forests, bluffs and rocky situations, 

 full of clear, rapid-flowing streams and 

 wild rugged mountain scenery, very little 

 disturbed by cultivation or lumbering; 

 wild flowers more abundant than in any 

 other part of the state; wild turkey 

 common and wild deer occasionally seen. 

 500 ft. general elevation. Talihina, 

 Frisco R. R. (h) 24 mi. east. — Chas.O. 

 Chambers. 



E. States Chiefly Grassland or Desert Grassland 



The grassland and great plains area 

 of North America extends from cen- 

 tral Saskachewan to southwestern Texas 

 with transitions from grassland to desert 

 reaching westward into New Mexico 

 and southward into Mexico in the valley 

 of the Concias river and in western 

 Chihuahua. Large areas occur in the 

 Canadian provinces of Alberta, Sas- 

 kachewan and Manitoba. The Dakotas 

 are very largely of this type. It includes 

 a small portion of western Minnesota 

 and of Northwestern Iowa, and large 

 areas in western Nebraska, Kansas, 

 Oklahoma and Texas. Montana, Wj'om- 

 ing and Colorado have large areas of 

 coniferous forest in their central or 

 western parts but since this was largely 

 treated under the various forest districts 

 these states are included here. 



1. TEXAS! 



By Alvin R. Cahn 



i. general conditions 



1. Topography 



Because of the great area of the state, 

 together with its unique geographical 

 position, Texas presents a region of great 



1 I wish to express my appreciation to Drs. W. L. 

 Bray, V. Bailey, and D. H. Wright for reading the 

 original manuscript and for many constructive 

 criticisms which have been embodied in the present 

 article; to Dr. V. E. Shelford I am indebted for 

 many suggestions which acted as guide lines in 

 working up a great deal of material. 



topographic diversity. For the most 

 part there is a general and steady rise 

 from the gulf coast northwestward, a 

 rise which reaches its culmination in 

 the great staked plains region of west 

 Texas, an elevation of 4000 ft. A break 

 occurs in this region, represented by the 

 valley of the Pecos River, and the high- 

 lands, encircling this valley in the south- 

 eastern corner of New Mexico, reenter 

 the state again as the mountain region of 

 the trans-Pecos country. Here the 

 highest altitude in the state is reached 

 in the Guadaloupe mountains, where 

 Guadaloupe Peak attains a height of 

 9500 ft. The slope is, therefore, from 

 the northwest to the south and south- 

 east. As would be expected in a large 

 region containing such a diversity of 

 elevation, surface conditions are exceed- 

 ingly varied: Mountains occupy the 

 trans-Pecos region; the Llano Estacado 

 or "staked plains" are high, treeless 

 grassland plains, extending into New 

 Mexico from northwestern Texas; there 

 is a great expanse of central hilly coun- 

 try, great prairie regions ; forest ; hot arid 

 desert: low swampy country, such as 

 that along the gulf. Soil conditions 

 vary as well, ranging from pure sand 

 through gray and red clays to the harder 

 limestones and great masses of igneous 

 rock. In the desert and semi-desert 

 country erosion plays and has played a 

 most important role, and is responsible 



