It may not have entirely felt like it over the weekend, but this is the time seasons change in Yellowstone National Park. Park Spokesman Al Nash says park plows are taking to the roads today, beginning to make their ways south through the park to open the roads. That, says Nash is no small chore. He explains that unlike roads that are cleared for travel throughout the winter, the interior roads in Yellowstone get packed and groomed for over-snow travel. Because of that, he says, “We can see very dense layers of ice or snow below some thick, heavy fresh snow which really makes road-clearing in Yellowstone quite a challenge for several weeks during the spring. Nash ways the plows will be working south toward Norris and Old Faithful; and also west from Madison Junction to West Yellowstone, Montana. That segment of road will be first to open on April 18th.