July 31-99. Monday Camp. XL. Started out from Treze Ouit Out with Roman and Cornice. Reviewing my section of yesterday. On the low slope of the dome beneath Treze Ouit Int, which is about 100 feet beneath in the Red Beds the base of the marine fauna collected a number of small fossils. This forms the rim of the Amphitheater. These are in the Upper Taurianic Sitting on the slope and looking South to Treze Out Int one can see the strata arching from the north, and northern east and west along the eastern sides of this upper portion of the arch and the free shore of the Omicron horizon is in large part replaced by a whitish sandstone while on the eastern slopes there is no sandstone in this zone. The distance across from east to east cannot be more than four miles and yet there is this marked change. All that I have seen proves to me that the Omicron horizon is not of fresh water origin. It lies conformable upon the marine fauna and conformable beneath the Dakota, which Knight (Catenius 2 pag. wrn)