490 Bulletin 47, United States National Museum. 



Professor Evermann has elsewhere described the locality as follows: 



Two-Ocean Pass is a high mountain meadow, about 8,200 feet above the sea and situated just 

 south of the Yellowstone National Park, in longitude 110 10' W., latitude 44 3' N. It is sur- 

 rounded on all sides by rather high mountains except where the narrow valleys of Atlantic and 

 Pacific creeks open out from it. Running back among the mountains to the northward are two 

 small canyons down which come two small streams. On the opposite side is another canyon down 

 which comes another small stream. The extreme length of the meadow from east to west is about a 

 mile, while the width from north to south is not much less. The larger of the streams coming 

 in from the north is Pacific Creek, which, after winding along the western side of the meadow, 

 turns abruptly westward, leaving through a narrow gorge. Receiving numerous small affluents, 

 Pacific Creek soon becomes a good-sized stream, which finally unites with Buffalo Creek a few 

 miles above where the latter stream flows into Snake River. 



Atlantic Creek was found to have two forks entering the pass. At the north end of the 

 meadow is a small wooded canyon down which flows the North Fork. This stream hugs the bor- 

 der of the flat very closely. The South Fork comes down the canyon on the south side, skirting 

 the brow of the hill a little less closely than does the North Fork. The two, coming together 

 near the middle of the eastern border of the meadow, form Atlantic Creek which, after a course 

 of a few miles flows into the Upper Yellowstone. But the remarkable phenomena exhibited 

 here remain to be described. 



Each fork of Atlantic Creek, just after entering the meadow, divides as if to flow around an 

 island, but the stream toward the meadow, instead of returning to the portion from which it had 

 parted, continues its westerly course across the meadow. Just before reaching the western bor- 

 der the two streams unite and then pour their combined waters into Pacific Creek ; thus are 

 Atlantic and Pacific creeks united and a continuous water way from the Columbia via Two-Ocean 

 Pass to the Gulf of Mexico is established. 



Pacific Creek is a stream of good size long before it enters the pass, and its course through the 

 meadow is in a definite channel, but not so with Atlantic Creek. The west bank of each fork is 

 low and the water is liable to break through anywhere and thus send part of its water across to 

 Pacific Creek. It is probably true that one or two branches always connect the two creeks under 

 ordinary conditions, and that following heavy rains or when the snows are melting, a much 

 greater portion of the water of Atlantic Creek crosses the meadow to the other side. 



Besides the channels already mentioned, there are several more or less distinct ones that were 

 dry at the time of our visit. As already stated the pass is a nearly level meadow, covered with a 

 heavy growth of grass and many small willows 1 to 3 feet high. While it is somewhat marshy in 

 places it has nothing of the nature of a lake about it. Of course during wet weather the small 

 springs at the borders of the meadow would be stronger, but the important facts are that there 

 is no lake or even marsh there and that neither Atlantic nor Pacific Creek has its rise in the 

 meadow. Atlantic Creek in fact comes into the pass as two good-sized streams from opposite 

 directions and leaves it by at least four channels, thus making an island of a considerable por- 

 tion of the meadow. And it is certain that there is, under ordinary circumstances, a con- 

 tinuous water way through Two-Ocean Pass of such a character as to permit fishes to pass easily 

 and readily from Snake River over to the Yellowstone, or in the opposite direction. Indeed, it 

 is quite possible, barring certain falls in the Snake River, for a fish so inclined to start at the 

 mouth of the Columbia, travel up that great river to its principal tributary, the Snake, thence 

 on through the long, tortuous course of that stream, and, under the shadows of the Grand 

 Teton, enter the cold waters of Pacific Creek, by which it could journey on up to the very crest 

 of the Great Continental Divide, to Two-Ocean Pass; through this pass it may have a choice of 

 two routes to Atlantic Creek, in which the down-stream journey is begun. Soon it reaches the 

 Yellowstone, down which it continues to Yellowstone Lake, then through the lower Yellow- 

 stone out into the turbid waters of the Missouri; for many hundred miles it may continue down 

 this mighty river before reaching the Father of Waters, which will finally carry it to the Gulf 

 of Mexico a wonderful journey of nearly 6,000 miles by far the longest possible fresh-water 

 journey in the world. 



We found trout in Pacific Creek at every point where we examined it. In Two-Ocean Pass we 

 found trout in each of the streams and in such positions as would have permitted them to pass 

 easily from one side of the divide to the other. We also found trout in Atlantic Creek below 

 the pass, and in the upper Yellowstone they were abundant. Thus it is certain that there is no 

 obstruction, even in dry weather, to prevent the passage of trout from the Snake River to 



