78 GEOLOGICAL SURVEY OF THE TERRITORIES. 



liiiiestone on the west side of the river is a considerable thickness of 

 the rnsty-brown sandstones, pudding-stones, clays, &c., that charac- 

 terize the Sihirian near the Three Forks ; but these beds are thinning 

 out very ra])idly in their southward extension. Spanish Creek flows 

 into the Galhitin from the divide on the west side, and nearly separates 

 the unchanged strata above from the gneissic rock below. A few patches 

 of limestones occur here and there. In the limestones on the east side 

 of the Gallatin, g^reat quantities of fossils occur, ProducfussemireticuJafus, 

 P. lonrjispimiH^ IStrophomena analoga^ Hemipronctes crenistria, and many 

 others (see catalogue of Mr. Meek) of Carboniferous age. On the west 

 side of the river thelimestoue-ridgessoon disappear and the massivegran- 

 itoid rocks appear, rising to an enormous height, covered with great quan- 

 tities of huge fragments. On theeast side, the Carboniferous and Silurian 

 beds extend up for about Ave miles, when the^' slowly disappear over the 

 summits of the granitic mountains. At lirst the Carboniferous lime- 

 stones extend down to the water's edge, but in ascending the river the 

 strata rise rapidly until the entire mass is exposed, resting upon the 

 ^^'anitic grouj). Although there is no positive non-conforu^ity between 

 the Carboniferous and Silnrian, yet there ai)pears to be a well-defined 

 physical line of separation. The Silurian limestones are more massive, 

 brittle, cherty, and have an ancient look, while the Carboniferous beds 

 are more pure lijnestone, and with thin, well-defined layers. These 

 upper limestones also have a more modern ai)pearance. The sides of 

 the mountains on both sides of the Gallatin, from crest to crest, are 

 wonderfully rugged and ])icturesque. Tlie limestones are frequently 

 weathered into the most i^eculiar columns, while the granites are worn 

 into grand, castellated forms. The crest of the ranges on the entire 

 divide on the east side is composed of volcanic rock, while on the west 

 side the central mass is granitic, rising in high, sharp peaks, 10,000 to 

 10,500 feet above the sea. The pines cover the sides of the mountains 

 quite thickly in many places, sending their roots among the rocks 

 where the descent is almost vertical. About ten miles above the 

 entrance of the canon the granitic rocks rise to the surface on the east 

 side of the Gallatin, and extend ten miles up the river in full force on 

 both sides, rising quickly to a height of 2,000 to 2,500 feet above the 

 bed of the river. At first, detached beds of limestone may be seen upon 

 the high granite-walls, as they disappear ui)on the summits of the 

 mountains. The little streams, as they flow down from the divides on 

 either side, have cut fearful gorges through the granites. The narrow 

 valley on both sides of the river is covered with immense rounded 

 granite-bowlders, rendering the traveling very difficult. For a dis- 

 tance of ten miles we were obliged to travel with our pack-train very 

 slowly and with great risk. In no part of the West have we found a 

 more difficult trail, and this may account for the fact that so few per- 

 sons have ascended the stream. As we crossed one of the little streams 

 that flow into the Gallatin from the west side, we observed that the 

 water was very muddy. Mr. Sloaue, a prospecter, who accompanied 

 us for protection while he was searching for mines, suspecting that 

 somewhere near the head of the stream a fellow miner had found a good 

 thing and was working it out, quietly followed the stream up to its 

 source. Lie found near the head that a few^ days before lightning had 

 struck the ground, plowing it up in long lines sometimes 100 yards 

 or more and six feet in depth. The pines grew very thickly, but over 

 an area 150 feet wide and about COO yards long the trees were torn 

 down and broken in pieces. Trees two and a half feet in diameter were 

 broken off and were thrown several huudrwl yards down the stream. 



