This is it, your last chance to see a tree on the Dalton Highway. Welcome to the arctic tundra, the word tundra actually means “treeless uplands”. The subsoil in this area consists of permafrost, which is permanently frozen soil. Only vegetation with a very shallow root system can survive this far north. Take a break and check out the interpretive signs with information on the transition from the boreal forest to the arctic tundra.