<Dl> <Dd> <Dl> <Dd> On the Northwest . The Arctic Ocean between Lands End, Prince Patrick Island, and C. Columbia, Ellesmere Island . </Dd> </Dl> </Dd> </Dl> <Dd> <Dl> <Dd> On the Northwest . The Arctic Ocean between Lands End, Prince Patrick Island, and C. Columbia, Ellesmere Island . </Dd> </Dl> </Dd> <Dl> <Dd> On the Northwest . The Arctic Ocean between Lands End, Prince Patrick Island, and C. Columbia, Ellesmere Island . </Dd> </Dl> <Dd> On the Northwest . The Arctic Ocean between Lands End, Prince Patrick Island, and C. Columbia, Ellesmere Island . </Dd>

When was the last time the northwest passage was open