EXTINCT VOLCANO — ATWOOD 



315 



of pumice and fragmental material similar to that found in Sun 

 Notch to the east. Back from the rim where the till and pumice 

 covering has been partially removed by wind and rain, some bedrock 

 outcrops exhibit striae. One and a half miles south of the rim, close 

 to the highway, good morainic topography indicates that glacial ice 

 once covered part, if not all, of the slope west of Vidae Ridge. 



Munson Valley (17). — Directly east of the Government camp and 

 superintendent's office in Munson Valley is one of the best morainic 

 evidences of glaciation to be found in the park. While striae are 

 very scarce, the curving form of the ridges and their hummocky 

 topography leave no doubt as to their glacial origin. Unlike most 

 of the glacial features thus far reported, these moraines are not 

 buried by pumice. 



KETTLE HOLES 



PUMICE 



';,^""<^.-y;^:'<^'V.^;.'^- I J 50 FEET :'\ 



Figure ll. — Buried kaine aud kettle topography on the Middle Fork of Annie Creek 



Locality 18. 



Middle Fork Annie Creek (18). — Three miles south of the govern- 

 ment camp between Middle Fork and Annie Creek is a most inter- 

 esting topography resembling kame-and-kettle moraine. Directly 

 opposite, on the other side of Annie Creek along the highway north 

 of Pole Bridge Creek, is a similar topography. In both areas there 

 are numerous hills of pumice separated by depressions in pumice. 

 Not until a cross-section of the material was discovered in the valley 

 of Middle Fork a little over a mile above the junction of that stream 

 with Annie Creek did an explanation come to light (fig. 11). In the 

 bottom of the V-shaped gorge were hundreds of large polished bould- 

 ers that certainly did not originate from the pumice formation. On 

 closer examination several of these boulders were found to be striated. 

 With this clue a careful study was made of the walls of the gorge. 

 The upper 20-30 feet were composed of dry pumice, while the lower 



