We do lots of lessons in Iwappara and find that it is one of the best resorts for learning skiing and snowboarding in the Yuzawa area. Every time we head out that way we drive past Snowmobile Land which makes its home in the park close to the summer Aurora Leisure Pools.
If you are looking for a break from the slopes and some serious fun, this is well worth checking out. There are a whole range of courses but their recommended program for English speakers is the 30 minute or 60 minute trial course. You get to whizz around on one of their snowmobiles during that time and it is seriously exhilarating. Highly recommended.
It is best to let them know that you are coming. The Snow Country Tourism info office outside the West Exit of Echigo-Yuzawa Station can help you book, and then you'll just have to make your own way there. Let us know if you need any further information on snowmobiling in Yuzawa.