Idaho can be divided into three major geographic areas: the Rocky Mountains, the Columbia Plateau and the Basin and Ridge Region. The Rocky Mountains is the state’s largest geographic region and extends from the Idaho Panhandle (the narrow strip of Idaho that runs between Washington and Montana) south and along the Wyoming border. This area has steep gorges, deep canyons and swift streams and rivers. The Bitterroot Mountain Range lies along the Montana border in the Idaho Panhandle.

The Continental Divide passes through Idaho in the Bitterroots. The Columbia Plateau Sweeps out of Washington, into Idaho at the base of the Idaho Panhandle, and follows the Snake River across southern Idaho. The Snake River Plain, built up of lava flows, is a strip of land 20 to 40 miles wide on each side of the Snake River. The Basin and Range Region lies in southeastern Idaho and includes part of the Rocky Mountains. It has grassy plateaus and deep valleys in the mountainous sections.

With 80 recognized mountain ranges, Idaho is home to some of the most spectacular scenery and most rugged landscapes in the United States. Idaho has 50 mountain peaks higher than 10,000 feet. The highest point in the state is Borah Peak, 12,662 feet above sea level.

The Coeur d'Alene Mountains in the northern Panhandle is triangular area of mountains stretching from Lake Pend Orielle in the north to Coeur d'Alene Lake in the south. The highest peak in the Coeur d'Alene Mountains is Grizzly Mountain at 5, 950 feet. The Bighorn Crags, bare granite worn into sharp ridges and spires, are found in the Salmon River Mountains. This mountain range is almost completely circled by the Salmon River.

South of the Salmon River Mountains are the impressive Sawtooth Mountains. These are an extremely rugged series of granite peaks and beautiful meadows and alpine lakes. There are 33 mountains in this range higher than10,000 feet. The Seven Devils Mountains rise along Idaho's border with Oregon in the west. Nearby is Hells Canyon, the deepest river gorge in North America at almost 8,000 feet (2,435 m). It was carved over millions of years by the Snake River. In central Idaho, the Lost River Range extends 70 miles from the Salmon River almost to Arco. This is a vast wilderness of snow-capped peaks and home to Borah Peak, as well as six other 12,000-foot peaks. The Lemhi Range runs southeasterly for about 100 miles from the Salmon River to the Snake River Plains. The highest point in the Lemhi Range is Diamond Peak at 12,197 above sea level. Further south, the Blackfoot Mountains form a group of barren ridges between Idaho Falls and Soda Springs. Wolverine Canyon, a scenic gorge, is on the western slope of the Blackfoot Mountains.