other unique experience of that night was a lunar rainbow, the only 

 one I ever saw. It was a pale ghost of a rainbow, but perfectly distinct 

 and standing out strongly against the black clouds. 



We followed up Ham's Fork almost to the Idaho line and there we 

 found what we were in search of, a fine exposure of the geological for- 

 mation known as the Green River Shales. They are very finely lami- 

 nated and resemble the Florissant shales which we had exploited the 

 year before in Colorado, but they are pale bufl, instead of grey and, 

 geologically speaking, are very much older. Tearing out large blocks of 

 the rock with pickaxes, we would split them with tableknives into 

 plates of half an inch, or so, in thickness and almost every slab had fos- 

 sils on it. The Green River Shales are famous for their beautifully pre- 

 served fossil fish, but leaves and insects are also abundant. We secured a 

 fine collection of these exquisite fossils and then began to think of turn- 

 ing homeward. Reversing our steps, we reached the railroad and fol- 

 lowed that to Church Butte, where we turned southward to Spanish 

 John Meadow; there we found some beautiful fossils and I, strange to 

 say, was the most successful. 



Then we made a "pack camp" near the top of Twin Buttes, accessible 

 only by a bridle path; nothing on wheels could come anywhere near it. 

 It was by far the most beautiful camp that I ever had in Wyoming 

 (except those in the snowy Absaroka Mountains in 1884) and I twice 

 returned to it, in 1885 and 1886, and always with success in collecting. 

 The double-headed butte is capped by a thick mass of coarse pudding 

 stone, which causes the flatness of the top and makes the butte re- 

 semble the famous "kopjes" of South Africa, which played such a con- 

 spicuous part in the Boer War. Beneath this capping rock issued a 

 spring of the clearest and coldest water which made a charming little 

 oasis of grass and trees; first a grove of quaking asp and, below that, 

 one of tall spruces. From the top of the butte may be had one of the 

 wildest and strangest views that I ever beheld. Several thousand square 

 miles of bad lands, from Pilot Butte, on the north, to the Uinta Moun- 

 tains on the south. From that great height, the country looks like a vast 

 relief map, but utterly dead and desolate, with no green thing in sight, 

 save along the infrequent streams. 



The homeward journey by train offered no incident worthy of a 

 place in this chronicle. At Princeton I found many changes due to my 

 Grandfather's death. My Mother and Grandmother had moved to 

 Morven and my Uncle Arch had gone to his father's house. My plans 

 were exceedingly vague, beyond the settled intention of proceeding to 



C81] 



