246 E. L. Furlong— Exploration of Samwel Cave. 



used by animals or for their remains to reach it, is shown by 

 the relative positions of the two entrances. Though the 

 former entrance to the fissure in chamber one is closely sealed, 

 its outer opening could only be from the top of the cliff the 

 cave is in. The entrance to chamber two from the canyon bed 

 is a hundred or more feet below the point where the fissure 

 entrance was probably located. The additional time required 

 for cutting of the canyon to the depth of the lower entrance 

 would be considerable. 



The foregoing reasons, viz : the faunal difference and the 

 probably greater age of the entrance to chamber one, tend to 

 show that the fissure deposit is older than the deposit in cham- 

 ber two. 



While the faunas of Potter Creek Cave and Samwel Cave 

 are both Quaternary and are closely allied, there are some dif- 

 ferences that suggest difference in age. Preptoceras and the 

 Porcupines are present in Samwel Cave and absent from Pot- 

 ter Creek Cave. Arctotherium, Camelus, and Mastodon are 

 present in Potter Creek Cave and absent from Samwel Cave. 

 These faunal differences are probably to be correlated with a 

 difference in the physiographic relations of the Samwel Cave 

 and indicate that it is of somewhat later origin than the Potter 

 Creek cave. In support of this hypothesis, the river terraces 

 of the McCloud canyon offer some evidence. 



On both sides of the McCloud canyon at Samwel Cave sev- 

 eral distinct terraces are visible. Across the McCloud, south 

 of Bollibokka, well-defined terraces are cut in Hirtz Mt. ; the 

 lowest of these is 27 feet above the river. Above the latter, 

 approximately 150 feet higher, is a smaller terrace. Between 

 this and a terrace approximately 300 feet higher several small 

 benches occur. The 177 ft. terrace corresponds to a level but 

 a short distance below the canyon cave entrance. The 300 ft. 

 terrace is on a level with the top of the cliff over the main 

 entrance to the cave. One of the small benches between the 

 177 and 477 ft. terraces corresponds to the level of the main 

 entrance itself. It is probable that when the McCloud river 

 flowed at a level 477 ft. higher than its present height opposite 

 the cave, and when making the terraces at that height on Hirtz 

 Mountain, the cave was being partly carved out by solution and 

 subterranean water flow. During subsequent river cutting to 

 the terrace in front of the upper cave entrance, the large 

 chambers were formed. The time represented by the cutting 

 between this last terrace and the one just below the canyon 

 entrance was the period when mammals inhabited portions of 

 the cave and the deposit in chamber one was formed. During 

 the latter part of this period chamber two was opened and 

 occupied. When the river cut to a still lower level and the 



