I hope you make it to Alaska for a visit someday Manuel. I'm not much of a wildlife photographer (and certainly not with a TLR), but there are some great opportunities and places in Alaska to see and photograph big brown bears in the wild (taking appropriate precautions of course). The McNeil River and Brooks Falls (Katmai National Park) are two that come to mind.
My own photos of Alaskan "wildlife" are usually less impressive than the big grizzlies, moose and other animals that most people want to see on a trip to Alaska. I think I need a 250mm lens for my Mamiya TLRs. ;-)