Montana’s borders rope in just over 147,000 square miles, making it the fourth-largest state behind Alaska, Texas, and California. The northern edge of the state spans the Canadian province of Alberta and catches two thirds of Saskatchewan and the eastern part of British Columbia  to boot. North and South Dakota lie off to the east, Wyoming flanks much of the south, and the Idaho state line rims the Bitterroot Mountains at the western and southwestern borders.
Western Montana is where the state’s name (from the Spanish word for mountainous) rings particularly true: Steep pitches and narrow north-south valleys line up from the Idaho border to I-15. The Continental Divide enters from Canada in Glacier National Park , twists through the western mountains, and exits on a high flat stretch of land just west of Yellowstone National Park. Central Montana is particularly varied, with high plateaus and isolated mountain ranges running in no set direction. The eastern part of the state, where the landscape gradually flattens out into the Great Plains, is coursed by the Missouri and the Yellowstone Rivers and a host of smaller valleys. Contorted badlands, eroded terraces, and steep rimrocks fringe river valleys and dot the plains. Minerals, coal, and oil are concealed throughout the state, giving rise to the nickname “Treasure State.”