"Beyond these [the mountains south-east of the Park], is the valley of the Upper Yellowstone, which is as yet a _terra incognita_. My expedition passed entirely around, but could not penetrate it.... Although it was June, the immense body of snow baffled all our exertions, and we were compelled to content ourselves with listening to marvelous tales of burning plains, immense lakes, and boiling springs, without being able to verify these wonders. I know of but two men who claim to have ever visited this part of the Yellowstone Valley--James Bridger and Robert Meldrum. The narratives of both these men are very remarkable, and Bridger, in one of his recitals, described an immense boiling spring, that is a perfect counterpart of the geysers of Iceland. As he is uneducated, and had probably never heard of the existence of such natural wonders elsewhere, I have little doubt that he spoke of that which he had actually seen.... Bridger also insisted that immediately west[X] of the point at which we made our final effort to penetrate this singular valley, there is a stream of considerable size, which divides and flows down either side of the water-shed, thus discharging its waters into both the Atlantic and Pacific Oceans." [W] See Bibliography. Appendix E, "Explorations of the Yellowstone," etc. [X] Actually north-east. The Captain concludes this particular part of his report as follows: "I can not doubt, therefore, that at no very distant day, the mysteries of this region will be fully revealed; and, although small in extent, I regard the valley of the Upper Yellowstone as the most interesting unexplored district in our widely expanded country." Lieutenant Maynadier also contributes a few interesting observations upon this region. The vast importance of that extensive mass of mountains, as a reservoir of waters for the country round about, impressed him deeply. He says, somewhat ostentatiously: "As my fancy warmed with the wealth of desolation before me, I found something to admire in the calm self-denial with which this region, content with barren magnificence, gives up its water and soil to more favored countries." Of the Yellowstone River, he was told that it had its source "in a lake in the impenetrable fastnesses of the Rocky Mountains;" and that for some distance below the lake it flowed through a narrow gorge, up which "no one has ever been able to travel." [Illustration: MAP OF THE SOURCES of the YELLOWSTONE AS KNOWN BETWEEN 1860 AND 1870 FROM THE MAP _OF_ RAYNOLDS EXPEDITION OF 1860 _Opp. page 62._]