IS The Badland Formations of the Black Hills Region 



1855 and 1857 while in connection with the Lieutenant Warren 

 explorations of Dakota and Nebraska. He made a final visit 

 to the region in 1866 under the direction of the Philadelphia 

 Academy of Sciences. These parties collected vertebrate fos- 

 sils of the greatest scientific value and Dr. Leidy, whom I have 

 already mentioned, being recognized as best fitted of all men in 

 America to determine the nature of such fossils, was called upon 

 to write their description. Important papers rapidly issued from 

 his pen and each new description served to point out the need of 

 further exploration. In 1869 he published in the Journal of the 

 Academy of Natural Sciences of Philadelphia his monumental 

 work, "The Extinct Mammalian Fauna of Dakota and Nebras- 

 ka." In this large volume he brought together the accumulated 

 information of more than twenty years and fittingly closed what 

 serves as the first of three fairly defined epochs in the develop- 

 ment of knowledge of our badland formations. 



The year 1870 marks the beginning of the second epoch. 

 During this year the First Yale Scientific Expedition visited the 

 region under the direction of Prof. O. C. Marsh. Prof. Marsh 

 had made a brief visit of inspection two years befre this, but in 

 1870 he began the collecting of fossils. Prof. Marsh, not satis- 

 fied with the crude methods of collecting with which the earliest 

 investigators had to content themselves, undertook extensive 

 quarrying for the fossils, and developed also' more refined 

 methods of utilizing detached and broken pieces. In this way 

 a number of well-preserved, complete, or nearly complete, skele- 

 tons were obtained where before the material was weathered and 

 fragmentary. Complete restorations of skeletons disclose struc- 

 tural features much more readily than detached bones and im- 

 perfect fragments, and Prof. Marsh first extensively developed 

 this feature for the fossil vertebrates of the South Dakota and 

 other western badlands. He was thus able to emphasize more 

 easily the nature of these animals and to point out more clearly 

 their profoundly significant relation to present-day life. Prof. 

 Marsh continued field work for many years, the collecting being 

 done sometimes by expeditions directly from Yale, sometimes 

 by collectors hired for the purpose. Following the first Yale 

 expedition of 1870, other Yale expeditions were in the region 

 in 1 87 1, 1873, 1874, and hired collectors in 1886, '87, '88, '89, 

 '90, 94, '95, '97, '98. 



In this connection it may be stated that during the years 

 ;886-'90, much of the field work directed by Marsh was done 

 under the auspices of the U. S. Geological Survey, the materials 



