I have a buddy with Redbone Coon hounds and I've seen them run and swim the entire length of the Allagash. They're incredible. I don't know how its possible, but they just never stop. They're noisy as heck though, so you never get to see any moose when they come along, but they do ensure that there's not any food leftover.
Here's a picture of one during a spring trip on the Machias. The water was still quite cold, so she generally hitched a ride on top of the padded cooler seats.
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