The elk treated Friday was pregnant, which will give the researchers a chance to see what effect the contraceptive might have on animals that have already conceived.

DENVER - Biologists trying to limit elk populations at Rocky Mountain National Park and the National Elk Refuge in Jackson, Wyo., are trying birth control.

ROCKY MOUNTAIN NATIONAL PARK, Colo. (AP) -- Some elk in Rocky Mountain National Park will be tested for chronic wasting disease and given birth control starting next month to see how well the two ...