South Dakota School of Mines 



Bulletin No. 13. Plate No. 67. 



Photograph by O'Harra. 1909. 



A. Erosion detail of Titanotherium Beds near Big Foot Pass. 



Photograph by O'Harra. 1899. 

 B. Erosion detail of Oreodon Beds in the valley of Indian Creek. 



