South Dakota School of Mines. 



Bulletin No. 9. Plate No. 21. 



Photograph by O'Harra, 1909. 



Figure 1. The Great Wall between Cedar Pass and Big Foot Pass. 

 Protoceras Beds above. Oreodon Beds below. 



Photograph by O'Harra, 1909. 



Figure 2. The Great Wall between Cedar Pass and Big Foot Pass. 

 Protoceras Beds above. Oreodon Beds below 



.sESER 



Photograph by O'Harra, 1909. 



Figure 3. General view showing contact of the Titanotherium Beds with the overlying Oreodon 

 Beds. Near Big Foot Pass. The highest Titanotherium Beds here are red. 



