It is open seven days a week in the summer, but closes early in the winter. There are a few things you should know about Spirit Mountain’s buffet before you decide whether or not it is a good option for you.įirst, is the Spirit Mountain Casino Buffet available all day? In many cases, it is available all day during the summer and until late at night in the winter. Buffet service has long been available at the park, but this was the first time it had added an additional dining option. If you’re one of the thousands of people who visit Spirit Mountain in Jackson Hole each year, you may have noticed that it’s now operating a buffet.