The Boise National Forest was established in 1908. It is located in southwestern Idaho, north and east of Boise. It covers an area of about 4,100 square miles. Portions of both the Frank Church–River of No Return Wilderness and Sawtooth Wilderness Area are located in the forest. Payette National Forest borders it on the north, and Challis and Sawtooth national forests adjoin it to the east. The national forest is divided into two segments. The main part lies east of the North Fork Payette River, with the dimensions of about 110 miles north-south and 55 miles east-west. The majority of the forest is generally steep and mountainous, the Sawtooth Range constituting much of the area; elevation decreases toward the Boise River valley in the southwest. The highest point within the forest is Big Baldy, at 9,722 feet above sea level. The Middle Fork Salmon and South Fork Salmon rivers, the Middle Fork Payette River, and all three forks of the Boise River have their sources in the forest.
Shortly after the discovery of gold north of Boise in 1862, numerous mining communities sprang up in the area. As the deposits were depleted, many of the mining sites became lumbering or livestock-grazing outposts; logging and sheep ranching were important to the local economy. Most of the mining towns died out and became ghost towns. Logging remains an important use of the forest.
The national forest is a popular recreation area, noted for its fishing and hunting, hiking, and rafting on the Middle Fork Salmon River. Bogus Basin Ski Resort is a winter-sports center, 16 miles north of Boise, which is where the forest headquarters are located.