(1) The following regions are designated as trauma regions:

(a) the western trauma region, consisting of Beaverhead, Deer Lodge, Flathead, Granite, Lake, Lincoln, Mineral, Missoula, Powell, Ravalli, Sanders, and Silver Bow counties;

(b) the central trauma region, consisting of Blaine, Broadwater, Cascade, Chouteau, Glacier, Hill, Jefferson, Judith Basin, Lewis and Clark, Liberty, Meagher, Pondera, Teton, and Toole counties; and

(c) the eastern trauma region, consisting of Big Horn, Carbon, Carter, Custer, Daniels, Dawson, Fallon, Fergus, Gallatin, Garfield, Golden Valley, Madison, McCone, Musselshell, Park, Petroleum, Phillips, Powder River, Prairie, Richland, Roosevelt, Rosebud, Sheridan, Stillwater, Sweet Grass, Treasure, Valley, Wheatland, Wibaux, and Yellowstone counties.