A Chinook helicopter looks huge inside and out compared to any other helicopter in the Army inventory--until you try to fit a Humvee inside of it. Then the very big Chinook helicopter looks a lot smaller when you see a Humvee backing into it. The Humvee is just a couple of inches narrower than the cargo area of the Chinook. It also fits within just a few inches on top.
But it fits. Here are some photos: