Here is link to AK page on firearms which is interesting to say the least.
http://www.adfg.alaska.gov/index.cfm?adfg=hunting.firearms
Bullet placement is their number one criteria.
Here is one of their paragraphs on cartridge selection:
"Cartridge Selection
Alaska big game varies from the relatively small (deer, goats) to the largest game on the continent (brown bears, moose).
In general, hunters should select a larger caliber for the largest game. Cover type should also play a role in cartridge selection. Sheep and goats are almost always hunted in the mountains where long distance visibility is the rule. A smaller, flat-shooting cartridge may be best here. Deer in the coastal forests of Southeast Alaska are often shot at less than 20 yards. Moose in the Interior may be shot at intermediate distances. Select your cartridge based on the expected circumstances."
I added underline for emphasis which is what most folks would consider when hunting larger animals. I would also check with your guide as for their minimal caliber requirements since many do have them and will not accept anything less due to their own experiences. Heck, I know some elk outfitters that have strong opinions on minimal calibers due to chasing critters through the mountains is not what they like to do for sure.
So back to the OP question, is it enough? Yes but with a whole bunch of qualifiers. Behind the shoulder perfect broadside? Sure all day long. But who gets perfect standing broadside shots EVERY time they hunt an animal as big as a moose? I always like to take the least caliber that can handle most every type of angle shot imagine since you are on a trip maybe of a lifetime so you really want to be able to kill the animal when ANY shot presents itself. It may be the ONLY shot of your trip period so you surely want enough gun to make that shot.