Yellowstone National Park will open for its winter season at 8 a.m. Friday,

Visitors can travel the park's interior roads on commercially guided snowmobiles and snow coaches from the North, West and South entrances.

Visitors with the proper permits also can participate in the non-commercially guided snowmobile trips.

However, travel through the park's East entrance over Sylvan Pass to Lake Butte won't be available until Dec. 22, depending  on the weather.

Travel from Fishing Bridge to Lake Butte is closed until more snow accumulates on this section of road.

The road from the park’s North Entrance at Gardiner, Mont., through Mammoth Hot Springs to Cooke City, Mont., is open to wheeled vehicle travel all year.

Park officials say weather is extremely unpredictable and road closures or delays can occur with little or no warning.

They urge visitors come prepared with personal emergency survival equipment. Park officials also urge visitors to dress appropriately for outside activities.

Most stores, restaurants, campgrounds, and lodges are closed during winter.

However, the park still offers a variety of services.

At Old Faithful, the visitor education center, Geyser Grill, and Bear Den Gift Shop and the ski shop will open Friday. The Snow Lodge, Cabins, and the Obsidian Dining Room will open Saturday.

At Mammoth Hot Springs, the hotel, dining room, and ski shop will be open.

At Tower Junction, 24-hour gasoline pumps are available.

These services are open year-round: Albright Visitor Center, Yellowstone General Store, 24-hour gasoline pumps, medical clinic, campground, and post office

The park also offers warming huts at Canyon, Fishing Bridge, Indian Creek, Madison, Mammoth Hot Springs, Old Faithful, and West Thumb. Some huts are staffed during business hours. Food, restrooms, and water are available at some huts.

Yellowstone also offers activities such as ranger-led programs, cross country skiing, and snowshoeing.