NATURAL .UlEAS AND REGIONS 



S4'J 



southwest. The tough gumbo soils 

 of this arid region are much eroded in 

 some places and support only a small 

 range of plant and animal life. Trees, 

 such as cottonwoods, and hackberries 

 are found chiefly along th' 



most of which often go dry. .,... 



areas supply pasture only, when suffi- 

 cient moist uTv \s. 



c. The souii.t-. ~' ~ comprises 



the big Bad Lan . • hite River 



and their southern uplands, the sandy 

 loams and clays of which afford fine 

 pasture-land and many fine agricultural 

 tracts. This region consists mostly 

 of Miocene (Arikaree; — verj- little Plio- 

 cene and Pleistocene — while its greatly 

 eroded northern and northwestern parts, 

 known as the Big Bad Lands of the 

 White River, are e.xposures, on a grand 

 scale, of Oligocene CBrule and Chadron)' 

 age and support little plant life. 



These Bad Lands (Mauvaises Terres^, 

 about 50 by 75 mi. in extent, are among 

 the most picturesque erosional regions 

 in the world and their many varieties of 

 fossils are world famous. Here are 

 canyons, spires, walls, and many gro- 

 tesque formations, which yield remains 

 of prehistoric animal life of astonishing 

 variet}-, some of which are related to 

 modern animals such as turtles, camels, 

 and horses. This area is practically 

 unchanged except where an occasional 

 settlement on the lower flat ground has 

 resulted in cultivation of limited areas. 

 d. The fourth area, the Black Hills, 

 with their partly pine-clad sides, rising 

 above the plain to an altitude of 6000 

 to 7000 ft. above sea level, present the 

 most wonderful part of South Dakota. 

 In certain respects they are unsurpassed 

 in beauty and g interest by any 



other mountainous region in the world. 

 They intercept much moisture and on 

 this account plant* and animal life is 

 much more abundant than on the plains. 

 Bear, de- ' n, and antelope ''origi- 

 nally wil- 'W mostly in parks) arc 



3 0'Harra, C. C. The \Vh:t(> Rivor R-i'i T-anHv 

 S D. School of Mi:, 

 plates, 1920. (This 



''''''o^^Vc. C. 0-Harra-s Handbook of the 

 Black Hills. lo9 pp., 1913. 



among the larger mammal«. The plant 

 life partly ]> 'of tli- 



c' .Ijcr- 



ing and by hre. I 'OO by 



shaped uplift of Pro' 



and Mesozoic ' ' 



with va' ■ ' '- 



dykes be. 



ful metals and minerals. The whole 



region is in* ' " 



cany'- "•'■-.. .... . 



tific ■ and in . 



The rocky formations varj' from the 

 red and yell ' ' ' *" 



the white liii.- - - , . . "' 



at the outer borders of the Red V.. 

 while the more somber colors ■ ■> 



and ore-bearing str * '' • ' e 



pines and wide var. f 



the interior in a way which one may 

 never forget. 



II. BIOT.\ (e. j. p.) 



A. Grassland 



a. Tall grass prairie {True p- 

 Clemenls). The t:;" 



pogon prairie occuj . f' 



of the state,* except that part in which 



IS forest growth is i 



11 .1 111.' 



stre:j.m ■- 



This is u . 2 



which the blue steins {Ai 



furcatus and A. = 



. I . / , . . 



are i: 

 Many other herbaceous plants bearing 



bea " " 



yi^i - s prairie 



of eastern South Dakota arc pr- 

 found such raa- ' 



Plains 



badger (Turithd tasus subsp 



covote 



gopher {Gfotni/a 



