Since when did the musk ok become so rare in the U.S. ? I remember that i saw musk ox at brookfield zoo in the eighties and i have a vague memory of seeing them at San Francisco zoo once. I think i also saw them at Toronto zoo, also back in the eighties. If you check zootierliste it seems that muskox are now easier to find in europe. What a pity, i remember they were impressive animals.