We have been planning to visit Yellowstone for a long time but getting there has always been an excuse. 2 days drive from San Fransisco or an expensive flight to one of the surrounding airports which are within 2 hours driving or more. But finally we decided to go for it and in December of 2014. So we drove. It was a long ride, we stopped at Twin Falls, ID on the way and enjoyed some nice sceneries on the way.
Before traveling to Yellowstone in the winter there are some preparations to do. The roads inside the park are closed except for the Grand Loop Road, connecting from Gardiner, MT. (North Entrance) through Mammoth Hot Springs and all the way to Cook City, MT. All other roads are open for snow-coach and snowmobiles only. However, during our trip the snow wasn't deep enough and in some places snowmobile access was not allowed either. Most of the wildlife can be seen along the Grand Loop Road, especially wolves, Ram, Moose and huge herds of Bison.
The best source of information Recreation.gov website. They will response to your emails and will provide all information that you need.
Plan your trip ahead of time - Which entrance?
If you want to travel along the Grand Loop Road with your own car then you should plan on staying in Gardiner and enter through the north entry gate. You can also spend your entire vacation either in Old Faithful Lodge or Mammoth Lodge. They are the only two lodges open inside the park in the winter. to get to Old Faithful you must leave your car outside the park, by the West Entrance, and schedule a pickup from there. The road from Gardiner to Mammoth is maintained so you can easily drive there. Coming from the south gives you fewer options to stay and at higher prices. Jackson is about 60 miles from the South Entrance and while Moran is closer (28 miles) it offered us only one hotel and higher prices, and snowmobile rentals are also higher than in Gardiner. (Snowmobile rentals will be discussed later).
Gardiner offers several places to stay, the Best Western is probably the most comfortable one. We stayed in the Riverside Cottages, which is a nice place and inexpensive but make sure to get a larger room if you stay there. Also, the AC wall unit doesn't work that great in the cottage that we stayed in.
Snow-Coach or snowmobiles??
We prefer the snowmobile adventure but it can be very cold.. We were lucky and during the 3 days of riding the temperatures during the day didn't fall below 17-20 degrees Fahrenheit. The following 2 days were much colder, down to 2 degrees Fahrenheit and I don't want to think what it would feel like on a snowmobile, even with the 7 layers and warming pads that my wife put on herself..
Non-Commercially Guided Snowmobile Access Program
This new experimental program started in winter 2014/2015. Basically, it allows private groups to travel around the park on rented/privately owned snowmobiles without the need to hire a commercial guide. You can have up to 5 snowmobiles in your group and only one group permit per day is given for each of the 4 entrances (the North-East Entrance is closed in the winter). You can read more information about this program on the Recreation.gov website.
We Googled and found Yellowstone Year-Round Safaris. We booked our snowmobiles rental through Deborah and if we ever go back there then we will definitely use their services again and we will also stay at the Best Western hotel, which is where they operate from. Simply, their service is exceptional, their prices are relatively low and the quality of their machines and equipment (helmets, suits, boots) is the best. One little con - The snowmobiles that we received from them didn't have seat warmers but they did have throttle warmers (for your hands and thumb).
Group Snowmobile Tours
These are available from Gardiner, Old-Faithful, at the South Entrance (although more expensive) and I believe you can book them also at the East and West Entrances but didn't check You can easily Google for that information. (Sorry..:-)
What to take?
Camera. If you love nature then do yourself a favor and take a camera, not a "smart-phone".. Other than that - Warm cloths, warming pads, emergency/survival kit, shovel, tires chains for your car, replace your windshield washer to a -40 degrees rated fluid!! (Trust me, I always forget to do this and it is very frustrating..)
We spent 6 days at the park and 7 nights in Gardiner. The first day we just took easy, drove along the Grand Loop Road and saw some wildlife. On day 2 we just took our rented snowmobiles on a short trip to get used to the conditions. On day 3 we rode from Gardiner to Canyon and back. It is a one-day trip. Carry food with you since the lodge and restaurant in Canyon are closed but the visitor's center is open and you can warm up in there. Don't try to push it all the way to Old Faithful as well unless you are planing to spend the night there. On day 4 we rode to Old Faithful. It is about 50 miles from Mammoth Springs and is a long ride so be prepared. The snow was fresh and deep powder when we were there so the deep tracks created by the Snow-Coach buses really made it bumpy so be aware of that. The 2 remaining days we just drove our car, again, along the Grand Loop Road to see more wildlife. Wolves are harder to spot but we spotted them twice, although they were too far away to photograph. If you insist on driving all the way to Cook City then you will find one open restaurant and a lot of snowmobile activities.