SMITHSONIAN EXPLORATIONS, 192/ 



71 



The higher ijortion of the Rocky Mountains in Colorado are still 

 yielding many new species of flies, though numerous collectors have 

 heen there. I had hoped to make a stop at Tennessee Pass, at 10,430 

 feet altitude, where I had collected twice hefore, hut my plans necessi- 

 tated a rather early start from Washington and the season was still too 

 early at the Pass, with freezing temperatures every night and cold 

 rains by day. However, I stopped on the South Fork of the Platte 

 River west of Pike's Peak at about 8,500 feet altitude and found good 

 collecting ; my camp here was a very satisfactory one. 



Fig. 73. — On Ten Sleep Creek, Big Horn Mountains, Wyoming. 



The Black Hills of South Dakota are important in the distribution 

 of the mountain forms of life, since they represent the easternmost 

 extension of the Rocky Mountain region. In 1892 I had collected 

 there for two weeks, the results being now incorporated in the National 

 Museum. Since the Hills are at some distance from all the transconti- 

 nental railroads, few entomologists have stopped there, and we possess 

 almost no flies from the region except those obtained on my former 

 visit. I had planned to make a stop there on this trip, but the season 

 was too late by the time I had come that far back. It was therefore 

 deemed expedient to visit the Hills on another trip, in the earlier part 

 of the summer. 



These were the chief localities included in the plan of the trip, but 

 I had opportunities to collect in the forested foothills of North Idaho, 



