Visit the American Prairie Reserve, a conservation project in the heart of Montana that could eventually be home to 10,000 bison. The vision is to stitch together 3.5 million acres of public and private lands to form the largest wildlife park in the lower 48. But some nearby ranchers feel the push to build the APR is pushing them off their land, and they're mounting a resistance. We also try to solve the Great Elk Mystery: why are elk that have been exposed to brucellosis allowed to roam free in Montana, while bison are not?