I'm currently in Alaska and have seen a few a moose. This seems to be pretty close. I might boost the strength score a little bit, probably a 20. I would say that moose are stronger than any human could possibly be. Throw on a powerful charge attack for the males, and some type of rage for the females if they have young that they feel are threatened. The antlers on them are big even for their size, maybe give them the next size up for the gore attack.
MOOSE
Large Animal
Hit Dice: 5d8+15 (37 hp)
Initiative: +1
Speed: 30 ft. (6 squares)
Armor Class: 14 (-1 size, +1 Dex, +4 natural), touch 10, flat-footed 13
Base Attack/Grapple: +3/+11
Attack: Gore +7 melee (2D6+5) or hoof +7 melee (1d6+5)
Full Attack: Gore +7 melee (1d8+5) or 2 hooves +7 melee (1d6+5)
Space/Reach: 10 ft./5 ft.
Special Attack: —
Special Qualities: Low-light vision, scent
Saves: Fort +7, Ref +5, Will +1
Abilities: Str 20, Dex 12, Con 16, Int 2, Wis 11, Cha 6
Skills: Hide +1*, Listen +3, Move Silently +4, Swim +10
Feats: Alertness, Endurance
Environment: Cold and temperate forest, plains, and hills
Organization: Solitary
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: 6-7 HD (Large)
Level Adjustment: —
Powerful Charge:
Does double damage with a gore attack on a charge.
Skills: Moose have a +2 racial bonus on Hide and Move Silently checks and a +4 racial bonus on Swim checks. *In forested areas, the Hide bonus increases to +4