If you meant 'without' going through Canada, that's possible too.
Most of the ferry's stop up in Haines, the farthest north point in S.E. Alaska. From there you must still drive into Canada and then back into Alaska.
But, in the summer there's a few ferry runs that go from Juneau straight across the gulf (that's why they're called 'cross gulf' trips
) to Valdez/Seward. You can skip Canada completely that way.