Atigun Pass, elev. 4739 ft. This is a very significant point of your journey. As you travel over Atigun Pass, you are crossing the Continental Divide. Rivers to the north empty into the Arctic Ocean, while rivers to the south empty into the Bering Sea. North of the Atigun Pass, the permafrost grows deeper (over 2,000 feet in the Prudhoe Bay area) and is present almost everywhere. South of the pass, permafrost areas become thinner and less prevalent. Watch for Dall sheep on the mountain sides.