This is the last weekend interior roads in Yellowstone National Park will be open to wheeled vehicles this year. Park Spokesman Al Nash says those wishing to visit the Park this weekend need to be self-sufficient since there are very few facilities still open. Then, he says, the Park crews will spend the weeks between now and December 15th preparing forthe winter season. Nash says among the transitions are the installation of snow markers, wood chips over areas where geothermal activity prevents snow from accumulating for snow machine use, erection of warming huts and placement of restrooms around the park. Nash says the interior roads will close to the public at 8:00 am Monday leaving only the North Entrance to Mammoth and on to the Northeast Entrance open to wheeled vehicles.