94 IOWA ACADEMY OF SCIENCES. 



could then see the whole of North Park, and much country in 

 every direction, probably, in all, 4,000 square miles. 



It is worth a trip to Colorado to stand on the top of Rabbit 

 Ear. In North Park we had found scoriaceous rock, which 

 called to mind forcibly the thought that a volcano was not far 

 away. In ascending Rabbit Ear it soon became apparent we 

 were on the very cone itself. Along the sides, in great pro- 

 fusion, were fragments of scoria, with occasional slag- like 

 masses. These continued to the top, where the two great ears 

 seemed to be firmer, more like trap, though not entirely 

 uniform, some portions weathering away much faster than 

 others. We had no means of determining our altitude at this 

 point, but from the snow about us (this was July 12th,) and the 

 Alpine vegetation, it must have been about 12,000 feet. 

 Steamboat Springs is northwest of Rabbit Ear about eighteen 

 miles. The pass here, at this time, was completely dry, but a 

 little earlier it is very muddy, almost impassable. On reach- 

 ing the western edge of the Park range, about seven miles 

 east of the Springs, it seemed as if we had come to a jumping- 

 off place. Far below us we could see the Bear with its beauti- 

 ful valley, green fields of oats and timothy, the little log 

 houses of the pioneers, and to the right in the distance, nestled 

 at the foot of this great mountain range, lay the village, 

 Steamboat Springs. The Yampa or Bear river here runs west 

 from Egerla Park, but at the Springs it turns south. 



The mountains to the south of the Bear appear to be much 

 lower, and differ in many respects from the Park range just to 

 the north There is not that boldness, that ruggedness, 

 although separated only by the narrow valley of the Bear. 

 The student of geology could not fail to be impressed with this 

 difference, as he stands at this point on the southern edge of 

 the Park range. On descending the mountain but few 

 extensive rock exposures are seen. Most, if not all, of the 

 rocks show^ metamorphism, being derived from what seems to 

 have been some kind of sandstone or argillaceous shales. No 

 marble was noticed in this locality. On the north side of the 

 Bear river, in the valley three or four miles east of the 

 Springs the region is thickly covered with well rounded 

 granitoid bowlders, some of which are ten to twenty feet 

 through. These have come from the mountains close by on 

 the north. The bed and banks of Fish creek are a mass of 

 bowlders, with very little filling between them. This is a 



