THE DAM 45 
was really too rapid and rough to be favorable for dam build- 
ing, though I saw where the beavers were beginning one and 
had the foundation laid part way across. This had disap- 
peared two years later. 
Perhaps the most peculiar location for a dam which has 
come to my notice is one that I was told about. A number 
of years ago my informant had occasion to visit a mining 
tunnel on a mountain several miles southwesterly from 
Colorado Springs. This mountain, while of no great eleva- 
tion itself, is much higher than the region immediately 
surrounding it. The tunnel was near the top of the moun- 
tain, and was about one-hundred and fifty feet long. The 
first twenty-five feet was in earth, and had been timbered 
with posts and caps, with lagging overhead and part way 
down the sides to hold up the ground. Aspen trees grew all 
about, evidently the attraction for the beavers. There was a 
good spring at the tunnel and the latter was wet, with 
enough water dripping from the roof to make a small stream 
which flowed from the mouth. All the water disappeared 
in the ground a couple of hundred feet or so below the tunnel 
dump. 
Beavers had built a circular dam about ten feet from the 
mouth of the tunnel in such a fashion as to impound the 
water from both the spring and the tunnel. The dam was 
about eighteen inches high, built of mud, aspen sticks and 
brush, and backed the water up in the tunnel for some dis- 
tance. Inside the tunnel holes had been dug in the earth at 
the sides of the timbered portion, and the earth from them 
apparently used in the dam. 
Many peeled aspen sticks were in the pond formed by this 
dam, and at the breast of the tunnel were more. The bark 
had been pulled from these last in strips, and used to make a 
nest or bed, which was about four feet in diameter and three 
high. It was hollowed out on top. 
