well I dont plan on hunting wyoming anytime soon, but if i had a few grand invested in a wyoming hunt. You bet your rear I will have the best cartrdige suited for those conditions something with a high ballistic coeffient and a alot of velocity for the least time of flight possible.
I'm thinking a 338 remington ultra mag loaded with lost river ballistics 250 grain J36 with about 100 grains of retumbo behind it.