467 
cipitation, given in inches, for four places in the region, Of these, 
Rapid City and Fort Meade are just outside the foothills, Spearfish in a 
canyon in the first range, and only Deadwood within the Hills proper; 
but the last is neither at a very great altitude nor even near the part 
that has the greatest precipitation. The table shows an increase of 
about 2 inches in the average annual precipitation for every 100 meters 
in altitude. If the precipitation of the higher parts of the Black Hills 
should be calculated on that basis, which would obviously be incorrect 
since many other meteorological conditions must be taken into consid- 
eration, the annual rain and snow fall around Custer would be about 32 
inches and that of the Harney Mountains about 40 inches or more, and 
still I do not think these figures are overestimated. The signs are 
unmistakable that the precipitation of the region around Harneys Peak 
is much larger than that at Deadwood. The more luxuriant growth of 
the vegetation, notwithstanding the higher altitude, the great abun- 
dance of plants that need a humid climate, as for instance ferns, mosses, 
liverworts, and lichens, and the innumerable streams that originate 
there, show that the precipitation of the southern Hills must be greater 
than that of the northern. 
For comparison | have included in the table the precipitation of four 
stations situated on the table-land between the Black Hills and the 
Rockies, and also of three stations within the Rocky Mountain region. 
It can be seen at a glance that the cemparison is favorable to the Black 
Hills. It would be naturally anticipated that the precipitation would be 
greater here than on the nearly treeless plains, but that it should be so 
much greater than in the places cited in the Rockies is more unexpected, 
It is intimated that the rains from the Gulf of Mexico do not reach the 
Rocky Mountains, and that the rains in that region come from the west. 
A place situated on the east side of the mountain, as is the case with the 
three stations given, would receive very little rain, as the moisture 
would be combed out by the mountains. 
Whatever the cause, the precipitation of the Black Hills is greater 
than that of certain places in the Rockies, as can also be seen from the 
table. Thesituation of Colorado Springs is similar to that of Rapid City 
or Fort Meade, and that of Georgetown or Helena can be compared with 
that of Deadwood. Even on the top of Pikes Peak, which takes away 
the rain from Colorado Springs, the precipitation is not greater than 
that of Deadwood, and I am sure that it would stand low in comparison 
with that of the Harney Mountains, if any records had been made at 
the latter place. 
