■^^".2.] HAYDEN ON TWO-OCEAN PASS. 225 ■ 



started down the mountain-cliannel (a) broke over the side into the 

 spring-hole (c), and flowed thence through channel c to the Pacific. 

 Lower down in the Two-Ocean channel are two places, shown by dotted 

 lines, where there are two old channels connecting in time of high water 

 with channel c, showing that a portion of the waters that started down 

 the mountain-side for the Atlantic was diverted toward the Pacific. On 

 the opposite side of the pass there is a similar depression in the breccia 

 wall, down which, at the time of the melting of the winter's snows, much, 

 water flows. 



The points 1) and d are close together, and the waters of the grassy 

 meadows, which lie between them, xDrobably separate, a part taking one 

 direction and a part the other. The little lake or marsh in the center, 

 of course, furnishes a supply or reservoir for both. Although the sim- 

 ple separation of water on a divide is not an uncommon occurrence, yet 

 the conditions observed in this case are rarely repeated, and have not 

 before come under the writer's observation. Small lakes upon the sum- 

 mit of a water-divide, with drainage from either side, are not uncommon 

 from the north line of the United States to Mexico. On the divide be- 

 tween the Yellowstone and Snake Eiver drainage, we often find small 

 lakes or reservoirs of water which in the wet season send small portions 

 to the Atlantic and to the Pacific. 



The following are examples of peculiar forms of drainage, which bear 

 some relation to that of the "Two-Ocean Pass ": 



Pigure 1 was observed by Mr. A. D. Wilson, of the Survey, in British 

 Columbia, between Fort Douglass and Lillooet. From & to c via a is 

 about 100 miles' travel. The lake at a lies on the summit of a mountain, 

 and is fed principally by springs ; its water runs either way through other 

 lakes 25 or 30 miles long, and finally flows into Frazer Eiver at b and c. 



In Fig. 2 is given a sketch of a case where a small mountain stream 

 divides and runs in two channels to the main creek. It occurs in the 

 Wind Eiver Mountains, ne^r the source of the Popo Agie Creek, a 

 branch of Wind Eiver. The small stream enters a depression at «, from 

 which its waters find their way out, partly to the right and partly to 

 the left of the rocky hill d, and empty into the main stream at h and c. 



ISTot far from this locality is another example similar to the above, in 



which a mountaip. torrent descends against the upper end of a great 



slide of rock, and is broken into two nearly equal parts, and so descends 



to the main creek. ^ 



i 



