Both! I went a few days early, then did go with a guy named Trent Sizemore for a few days, then back on my own for several days. I was there for 10 days. There is only one road open in winter to cars and I it is between Gardiner and Cool City which is Lamar Valley and lots of wildlife. I went with Trent as I thought he would have inside to what animals were where at certain times of the day. I really wanted a red fox in snow, which we never saw! Then a week or so after I left, they were everywhere! Trent is a nice guy, but I don’t feel I needed him. It was nice to have someone drive, but it was an expensive driver. You learn after a few days who the pros are that are there and what they drive. If you see their car stopped, you stop to see what they see! If you see them zoom by going another direction, you follow! Sometimes it is a good call, other times nothing! In the winter it is like a summer bear jam when there are wolves or something like that. You also learn the “Wolfies” the Wolf tracker people who are just looking at wolves a mile away with spotting scopes. So, if you want to go, just drive yourself. All you literally do is drive back and forth on the same road (not necessarily from end to end) and hope to be in the right place at the right time! You will also learn where the sheep are everyday, so you can always count on that and bison all over! There are snowcoach tours from West Yellowstone, but don’t do it unless you do a photo tour, or just want to go to Old Faithful etc. There is a guy named John Gerlach that does snowcoach photo tours. It could be good. Hope this helps, it you have more questions, let me know! I love that place and will go back in May!!