All terms in this list:

musher: One who travels by dogsled, especially in a race.

rugged: Broken into sharp or irregular points; full of asperities on the surface, or otherwise uneven; not smooth; rough; as, a rugged mountain; a rugged road.

experienced: Having experience and skill in a subject.

blizzard: A severe snowstorm, especially with strong winds and greatly reduced visibility.

checkpoint: A point or place where a check is performed, especially a point along a road or on a frontier where travellers are stopped for inspection

courageous: Of an action, that requires courage.