Traveling to Yellowstone National Park with your pet can be tough. They can only stay at a few of the cabins inside the park as many hotels are off-limits for them. Dogs also need to stay in the car throughout the park, or can only be kept on a leash of maximum 6 feet if they are within 100 feet of a front-country campground, the road or a parking lot. They are not allowed on the trails either, so what are you to do with your pet when traveling to Yellowstone National Park?
If you fully want to enjoy Yellowstone, get into the backcountry, hike all the trails, and admire the sights, you can leave your pet at one of the kennels located right outside the park. As a lot of visitors do this, it is best to make a reservation up front.
Should leaving your pet not be an option for you, limit yourself to the allowed areas or keep them in the car. Of course, you should only do this for short periods of time and with adequate ventilation. When you are done visiting Yellowstone, drive to the nearby Shoshone National Forest, where pets are allowed in all areas and can even be left off-leash in the backcountry, granted that you have trained them well and they are under voice control.
The Bridger-Teton National Forest is another nearby park where dogs can hike the trails alongside you. Just keep in mind to dress your pet in hunter orange or another bright color during hunting season, especially when you let it off-leash.