464 
at Custer July 13 to August 1. From the latter point I visited Oreville 
on July 17; Sylvan Lake and Harneys Peak, July 18 to 21; made a 
drive of 22 miles down French Creek July 22 and 23, and one into the 
Limestone District near the Wyoming line, July 25 to 30, extending 
probably 30 to 35 miles northwest of Custer. ; 
On August 1, 1 moved my camp to Minnekahta, visiting Pringle on 
the 6th. I then joined a party of naturalists from the University of 
Nebraska, in whose company I remained for the rest of the season. We 
camped at Hot Springs till August 11, when we moved to Custer. 
From this point, after visiting the Harneys Peak region on August 17 
to 18, we returned to Lincoln on August 22. 
GEOGRAPHY. 
The Black Hills are on the boundary line between South Dakota and 
Wyoming, the larger part lying within the former State. The center 
is a little east of the intersection of the forty-fourth parallel and one 
hundred and fourth meridian. The Black Hills constitute an isolated 
range about 120 miles long north-northwest and south-southeast, and 
40 to 50 miles wide east and west. <A little northwest of the Black 
Hills and separated from them only by the narrow valley of the Belle 
Fourche, is another much smaller spur, the Little Missouri Mountains, 
evidently belonging to the same range. The nearest mountains except 
those mentioned are the Big Horn Mountains to the west and the Lar- 
amie Mountains to the southwest. These are at a distance of 150 to 
200 miles and separated from the Black Hills, the former by the valleys 
of the Little Missouri and Powder rivers, the latter by those of the 
Cheyenne and North Platte. There are no mountains to the north, 
east, or south. 
Not only are the Black Hills an isolated range, but the surrounding 
high table-land is deeply cut on all sides by the branches of the Chey- 
enne River. The head of Inyankara Creek is due west of the center of 
the Hills. The creek runs in a northwesterly direction till it empties 
into the Belle Fourche. This runs northeast and then southeast, empty- 
ing into Cheyenne River. The bend is north of the range. Not far 
from the head of the Inyankara are the springs of Beaver Creek, a 
stream which flows south into Cheyenne River. The latter runs south 
of the Hills, then changes its course to northeast till it joins the Belle 
Fourche, and finally empties into the Missouri River. 
GEOLOGY. 
‘In order to compare the geological and floral districts of the Black 
Hills I give a summary of the geology of the region derived from the 
report by Henry Newton on the Geology and Resources of the Black 
Hills of Dakota.! 
‘U.S, Geog. and Geol, Survey of the liocky Mountain Region, 1880, 
