If you want to see condors, head to the High Peaks region near sunset and sunrise. For mammals, you'll likely see black-tailed deer, rabbits, and different species of bats.
Theodore Roosevelt National Park in the badlands of North Dakota is home to herds of American bison. You can often see them from the roads and campgrounds.
Mule deer can be found throughout the park, and in the South Unit, you have a chance to see elk and wild horses. More rarely, you may see bighorn sheep and pronghorn antelope.
Denali National Park & Preserve is a beautiful park that gives you a chance to see all of Alaska's "Big 5" species — bear, moose, caribou, Dall sheep, and wolves.