CANALS, TRAILS, AND LANDING PLACES 81 
spring or stream at a higher elevation, or, as in the case of 
some examined on Tower Creek, from the swampy ground 
in which the upper levels were dug. One of these was ninety 
feet long, the other one hundred and fifty feet, and they 
represented somewhat different engineering problems. The 
first mentioned was seventeen feet long at the pond level 
to the lower side of the dam, and twenty-three feet to the 
upper side, and above this was the remainder of the ditch. 
The lower level of course obtained its water from the pond 
and was fifteen inches deep; the upper level was nine inches 
deep and was supplied by seepage from the marshy ground 
about it. The canal varied in width from fifteen to eighteen 
inches. The face of the dam had a long gradual slope which 
must have greatly facilitated dragging logs over it. Aspens 
were being cut on the hillside above this canal. 
The second canal was about half a mile upstream from 
the other, and its lower end was twenty-three feet away 
from the creek, being connected with it by a trail, and at 
the time of the examination this was two feet above the 
water level. There was but one level to the canal, which 
was from three to four feet wide, and twelve to eighteen 
inches deep, the water supply being derived from a spring 
at the landward end. ‘The westerly bank of this canal was 
considerably lower than the other and was being raised by 
means of mud dug from the bottom. Aspens were being 
cut near the end of this canal (Fig. 38). 
Morgan described one canal 523 feet long leading from a 
natural pond, 450 feet from which was a short dam across 
the canal; 25 feet above that was another dam extending 27 
feet on one side and 75 feet on the other side of the ditch; 
and 47 feet farther up, at the head of the canal, was a third 
dam 55 feet long on one side of the ditch and 87 feet on the 
other. ‘There were pools of water above the head of the 
canal, and the long dams collected the drainage from these 
