That depends on how much snow is there.
U.S. Hwy 2 is open through the park as are some park roads. Most shops will be closed with a few exceptions. Be prepared for winter driving conditions and carry a winter survival pack suitable for up to at least 48 hours. There are areas where cell phone service is non existent,so be sure to check in with someone and tell them of your plans and have them know which area to send rescuers if you do not check in by such and such time. Weather changes can be very dramatic as well as avalanches, and bear encounters in some of the remote areas tho unlikely.
Yes, park roads are open year round to a particular point. Check the park road map to know exactly where they close from each entrance.
The major roads are kept open during winter months. Going to the Sun is closed as are all buildings and shops.
I don't know. Check the website.
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