Star Valley. Passing northward along the western border of Wyoming with Idaho, US 89 enters the Grand Teton National Park. Here, US 89 is the backbone visitor highway for two U.S. National Parks. Leaving the Tetons, the road enters a lesser known park, John D. Rockefeller, Jr. Memorial Parkway, before ending at the South Entrance of Yellowstone National Park. While US 89 and other U.S. Routes are officially discontinuous through the park, some commercially produced maps show these highways running inside Yellowstone National Park itself along its unnumbered roads and across the Wyoming–Montana state line. Montana US 89 enters Montana at the North Entrance of Yellowstone National Park. It traverses the width of the state before approaching Glacier National Park. At St. Mary, Montana, US 89 is the access highway to Glacier Route One, also known as the Going-to-the-Sun Road. The Kings Hill Scenic Byway passes through the Little Belt Mountains in the Lewis and Clark National Forest in Montana. The route is home to a wide variety of wildlife and provides many recreational opportunities for travelers on the route. The byway is a route that begins on US 89 at its junction with US 12. From the junction of the byway it travels north through the Lewis and Clark National Forest through the communities of Neihart and Monarch and on to its junction with US 87. The route offers access to the Showdown Ski Area and Sluice Boxes State Park. The route travels over the Kings Hill Pass which snow removal crews work to keep open throughout the winter season. The northern terminus of US 89 is at the Canadian border. There, the highway continues into Canada as Alberta Highway 2. History When US 89 was first created, it ran as far north as Spanish Fork, Utah. This was the case until 1934, when it was extended to more or less of its current alignment up to the Piegan Port of Entry north of Babb, Montana. North of Great Falls, Montana, US 89's current route was originally numbered as US 87 until 1934. After US 89 took over that route, US 87 ended in Great Falls until 1945, when it was extended to its current northern terminus near Havre, Montana. Prior to 1992, the southern terminus of US 89 was at Nogales, Arizona, and the highway proceeded to Flagstaff, Arizona, along what is now I-19, State Route 79, US