Answer:
Mushers and their dogs depend mostly on their senses of sight on a trail
Step-by-step explanation:
According to the given excerpt from Susan Butcher and the Iditarod Trail, Seppala could not see because he could not find a land trail and the wind was against them, but however Togo had to feel his way around the snow and found the trail before they could proceed to the next trail.
The conclusion that can be formed based on the information in the excerpt is that Mushers and their dogs mostly depend on their senses of sight on a trail.