Related Clues:

• Tireless racers?
• Olympic racers
• Luge and troika
• Olympics sleds
• They're pulled uphill
• Iditarod Trail transports
• Moves along tirelessly?
• Tundra transportation
• Huskies' burdens
• Iditarod needs
• Goes downhill, perhaps
• They can only take you downhill
• They go downhill fast
• They may be conducted into the ship over the snow
• They may follow teams