36 EEPOET UNITED STATES GEOLOGICAL SURVEY. 



water range on September 9, encamping on a very pretty little stream 

 ■within Carboniferous limestones. During the day we rode westward 

 along the summit of the ridge. From there we obtained our last good 

 view up the Sweetwater Valley. While on the highest points, a stiff 

 wind proved to be very troublesome to our work. The days were grad- 

 ually getting colder, and the addition of these gales was not an accept- 

 able one. Descending from the hills, we examined the bluffs and ridges 

 leadiug northward, thus completing the most westerly portion of the 

 work stiU remaining. 



On September 10 we turned our mules' heads eastward. The geology 

 of the region through which we were passing at the time required close 

 attention, and the marches of the train were comparatively short. Eid- 

 ing along the northern base of the hiUs, on the day following we reached 

 Elkhorn Gap and encamped there. TJp to this time we had been 

 favored with exceptionally good weather, but now it began to look threat- 

 ening. About twelve o'clock at night a severe rain-storm set in, lasting 

 only a few hours, but moistening us most uncomfortably. On the morn- 

 ing of the 12th we continued our march eastward, still remaining on the 

 north side of the hills. We made a number of stations on sedimentary 

 hills untn a violent rain-storm, followed by hail, forced us to abandon the 

 high points. While seeking shelter from the hail, we found a cave in some 

 limestone strata and utilized it to good advantage. Nevertheless we 

 were wet and cold. Despairing of being able to wait sufficiently long 

 until the steady rain which was then falling should have ceased, we rode 

 on looking for the trail of the pack-train. Although it was nearly oblit- 

 erated by the heavy shower, we succeeded in finding it. Trusting more 

 to our mules' unerring instinct than to our own judgment, we dropped 

 the reins and allowed them to proceed. Travelling along the slope of 

 the range, we crossed a number of small streams well tunbered with Cot- 

 tonwood. On one of them glacial moraines extended down far into the 

 vaUey. In this vicinity the hills were far more rugged than we had 

 found them elsewhere. Stratigraphical disturbances were denoted by 

 the character of the region. As we were slowly making our way up a 

 steep, shppery hill along an old game-trad, heavy banks of fog were 

 rolling up from the valleys and caiions below. Although these fogs are 

 generally not of very long duration, we were anxious to obtain a view of 

 the country beyond the ridge before descending. Urging our mules on 

 we lost the trail, and arrived on top only to find everything an absolute 

 light-gray blank. It was irnpossible to distinguish even a horseman for 

 a greater distance than fifteen feet. While waiting for a partial clearing 

 before proceeding any farther, a sudden momentary break in the impen- 

 etrable fog-bank before us revealed camp within two hundred yards. 

 Directly the gap closed again, but it required only a few minutes for us 

 to reach our tents. One of the most beautifal sights that can be found 

 in the mountains is the rapid rising of dense white clouds in canons. 

 EoUing up the slope of the valley, creeping along the walls, and finally 

 emerging from their confinement, the elastic masses gradually approach 

 the observer, until all of the earth is shut out from his sight excepting 

 the little spot upon which he stands. 



It was necessary to return to some points during the next day which 

 the storm had prevented us from visiting. Ascending the ridge from 

 camp, we found the sources of the glaciers high up in the hills. Cross- 

 ing one ridge after the other, while riding alternately through very fine 

 timber or meadows, we finally turned southward and reached the summit 

 of the hills. On the way, we heard elk "squealing" in various direc- 

 tions. Obtaining a good view into the low country southward, we rode 



