Much of Idaho has an unspoiled beauty, with rugged slopes and towering peaks, a vast expanse of timberland, scenic lakes, wild rivers, cascades, and spectacular gorges.

From the northern Panhandle, where Idaho is about 45 mi (72 km) wide, the state broadens south of the Bitterroot Range to 310 mi (499 km) in width. The Snake River flows in a great arc across southern Idaho.

In the central and north central regions and in the Panhandle there are tremendous expanses of national forests covering approximately two fifths of the state and constituting one of the largest areas of national forests in the nation. Idaho's jagged granite peaks include Mt. Borah, which is 12,662 ft (3,859 m) high. Hells Canyon, which at one point is 7,900 ft (2408 m) below the mountaintops, is the deepest gorge in North America. The state also contains Craters of the Moon National Monument and a protected grove of ancient cedars at Upper Priest Lake.

Rushing rivers such as the Salmon and the Clearwater, and many lakes, notably Lake Pend Oreille and Lake Coeur d'Alene (often described as one of the world's loveliest), make Idaho a superb fish and game preserve and vacation land. The state is especially inviting to campers, anglers, and hunters (Idaho has one of the largest elk herds in the nation). The state's climate ranges from hot summers in the arid southern basins to cold, snowy winters in the high wilderness areas of central and northern Idaho.

The unspoiled quality of much of Idaho's land has nourished one of the youngest of Idaho's businesses—the tourist trade. Sun Valley, one of the nation's best-known year-round vacation spots, is an example of the development of resorts in Idaho. Well-known as the first ski resort in the country, today Sun Valley has evolved into a quaint cultural mecca tucked inside a stunning mountain range. The towns of Ketchum and other Wood River communities offer fine restaurants, up-to-the-moment art galleries and boutiques, and a flourishing night life.