190 GEOLOGY OP THE YELLOWSTONE NATIONAL PARK. 



in the valley of Wolverine Creek, they cross the summit of Big- Game 

 Ridge, and pass down the steep east slopes, where they are well exposed on 

 both sides of Snake River just below the mouth of Crooked Creek. It can 

 not be said with any degree of assurance that this line is correctly laid 

 down, but no sandstones to the north or west of it have been recognized 

 as possessing the lithological characters of the Laramie. In the great 

 thickness of sedimentary sandstones represented in the several orographic 

 blocks it is possible that Laramie beds may occur, without geological evi- 

 dence as to their age. 



Mount Hancock. — Mount Hancock is not only the most prominent mountain 

 of Big Came Ridge, but it stands out as one of the most commanding 

 points along the southern border of the Park. It was named after General 

 Hancock by Maj. J. W. Barlow, who ascended the peak in August, 1871. 

 On a clear day the view from the summit is unsurpassed, either for detail 

 of topographic features immediately beneath or for the more distant pano- 

 ramic outline. It commands the Tetons, the dominant peaks of the Wind 

 River Range stretching far southward, the entire west face of the Absarokas, 

 the Park Plateau with its great lakes, the Snowy Range to the north, and 

 the Gallatin and Madison ranges to the west. 



Mount Hancock rises above Snake River at its east base for over 2,000 

 feet, and above the valley of the Snake at its west base for 2,500 feet. 

 The greater part of the mountain consists of yellowish-gray and white 

 massively bedded sandstone, which extends to within 400 feet of the 

 summit. All the beds forming the upper portion of the mountain have 

 been assigned to the Montana formation, although no organic remains have 

 been obtained from them. The southeastern slopes offer the best exposures 

 of these rocks, which dip to the southeast. It is estimated that there are 

 over 3,500 feet of sandstones. On the narrow ridge of sandstone just south 

 of the summit the beds strike north and south and dip 30° W. The 

 western spurs of the mountain are largely covered by forests and glacial 

 drift, rendering it difficult to obtain good exposures, but the beds for the 

 most part apparently dip west. North of Harebell Creek basic breccias 

 similar to those found on Coulter and Wolverine creeks, and part of the 

 same mass, extend along the west base of Mount Hancock. They present 

 a most irregular outline, the higher portions reaching an altitude of over 

 8,000 feet above sea level. 



On the summit of Mount Hancock a capping of dark rhyolite stands 

 out boldly, in contrast with the yellowish underlying sandstones. It rises 



