I'm with the guys that say "Tarpon in Alaska???" Don't think so.
Alaska is a beautiful place and there are lots of fish to catch. Kings, silvers, chum/dog, pinks//humpys....all salmon. then there are the Rainbow Trout, Grayling, Dolly Varden, Artic Char, and in some areas Pike.
I went when I was about 14 and have been trying to go back ever since. Fortunately, I will be headed up there in July once again. Mainly fishing for Kings and the native fish (trout, char, dolly varden, and grayling).
If you are mistaken on the 'Tarpon' fishing and it is fishing for Salmon or the native species, don't pass it up!
I don't see a lot of fun in halibut fishing, but they are good to eat!
BTW- Tarpon are a semi-tropical/tropical fish. They like warm waters. Most of the water I fished in Alaska previously was very cold, like 50 degrees or colder! Far from a tropical or semi-tropical region.