Too many variables. When are you going (weather), your age and physical abilities, what animal do you have to pack out, what is the country like (low and flat, high and steep), how long will you be staying in the backcountry, level of backwoods ability, solo or with a companion. Any concerns from grizzlies?
When I was young and full of pee and vinegar, packing an elk out 3 miles over rough terrain was doable but not a bunch of fun. And you not only have to get the animal out, but your camp as well, so that is several trips. It helps to have young, strong friends or a horse or two in situations like that.