Figure 63. — Snow Trails approaching passage 1 through the median barrier fence and continuing down path 1 to the Food 
Pen. These trails were made during the preceding night of December 19-20, 1948, immediately following the termi- 
nation of snowfall. Note the deflection to the right toward the first group of snow-covered traps and then a similar 
deflection to the left farther down the trail. This swerving of the trail was induced during the previous 2 weeks following 
the placing of the traps on either side of path 1 . 
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