4 GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 



necting tlie Pacific Eailroacl witb the Yellowstone Basin, Our principal 

 field of operation. From Fort Ellis, we passed eastward over tlie divide, 

 between the drainage of the Missouri and Yellowstone, to Bottler's 

 Eanch. Here we established a permanent camp, leaving all our wagons 

 and a portion of the i)arty. A careful system of meteorological obser- 

 vations was kept at this locality for six weeks. From Bottler's Eanch 

 we proceeded up the valley of the Yellowstone, surveyed the remark- 

 able hot springs on Gardiner's Eiver, the Grand Caiion, Tower Falls, 

 Upper and Lower Falls of the Yellowstone, thence into the basin proper, 

 prepared charts of all the Hot Spring groups, which were very numer- 

 ous, and continued up the river to the lake. We then commenced a syste- 

 matic survey of the lakd and its surroundings. Mr. Schonborn, with his 

 assistant, made a careful survey of the lake and the mountains from the 

 shore, and Messrs. Elliott and Carriugton surveyed and sketched its 

 shore-lines from the water in a boat. Careful soundings were also made, 

 and the greatest depth was found to be three hundred feet. From the lake 

 I proceeded, with Messrs. Schonborn, Peale, and Elliott to the Fire-Hole 

 Valley, by way of East Fork of the Madison ; then ascended the Fire-Hole 

 Valley. We made careful charts of the Lower and Upper Geyser Basin, 

 locating all the principal springs, and determining their temperatures. 

 We then returned over the mountains by way of the head of Fire-Hole 

 Eiver, explored Madison Lake, Heart Lake, &c. After having completed 

 our survey of the lake, we crossed over on to the headwaters of the East 

 Fork by way of the valley of Pelican Creek, explored the East Fork to its 

 junction with the main Yellowstone, and thence to Bottler's Eanch, which 

 we reached on the 28th of August. From this place we passed down the 

 Yellowstone, through the lower caiion, to the mouth of Shield's Eiver, to 

 connect our work with that of Col. Wm. F. Eay nold s, in 1860. From there 

 we returned to Fort Ellis. From this point I desired to examine a belt 

 southward to the Union Pacific Eailroad, that should connect, as far as 

 possible, with the belt explored on our way up to Fort Ellis in June. 

 We therefore passed down the Gallatin Valley to the junction of the 

 Three Forks, thence up the Jefferson Fork to the Beaver Head branch, 

 then up the Beaver Head to Horse Plain Creek, uj) the latter creek to 

 the main Eocky Mountain divide, thence across to the headwaters of 

 the Medicine Lodge Creek into the Snake Eiver basin and Fort Hall. 

 From Fort Hall we struck across the mountains between Black-Foot 

 Creek and the source of the Port Neuf to Soda Springs, at the head of 

 Bear Eiver; examined the Soda Spring district, and passed up the valley 

 of Bear Eiver, by way of Bear Lake, to Evanston, on the Union Pacific 

 Eailroad. At this point the party was disbanded, most of them re- 

 turning to their homes. A portion of the month of October was occu- 

 pied in reviewing points of geological interest along the railroad. 



Extensive collections in geology, mineralogy, botany, and all depart- 

 ments of natural history were made, some account of which is given in 

 subsequent portions of this report. 



