BOISE NATIONAL FOREST

national forest in southwestern Idaho, U.S., divided into two segments. The principal part lies east of the North Fork of the Payette River and is roughly diamond-shaped, with maximum dimensions of about 109 miles (175 km) north-south and 55 miles (89 km) east-west. To the west and separated from it by the valley of the North Fork of the Payette River is a narrow outlying part of the forest, about 37 miles (60 km) north-south and 12 miles (19 km) east-west at its widest point; most of it, however, is much narrower. The main portion of the forest is generally steep and mountainous, decreasing somewhat in elevation toward the Boise River valley in the southwest. The rugged Sawtooth Range covers much of the eastern part; the highest elevation within the forest is Big Baldy, 9,722 feet (2,963 m) above sea level. The Middle and South forks of the Salmon River, the Middle Fork of the Payette River, and all three forks of the Boise River, have their sources in the forest. Following the discovery of gold north of Boise in 1862, numerous mining communities sprang up in the locality. As the deposits were depleted, many of the mining sites became lumbering or grazing outposts; the cutting of Ponderosa pine and sheep ranching were important to the economy. Some of the mining towns, however, died out and are now ghost towns of interest to tourists. Fishing, hunting (bear, deer, elk, mountain goat), hiking, and rafting on the Middle Fork of the Salmon River are all popular. Parts of both the Frank Church Wilderness (formerly Idaho Primitive Area) and the Sawtooth Wilderness Area are in the forest; these scenic wilderness areas, where commercial exploitation is forbidden, are kept virtually roadless. Bogus Basin Ski Area is a winter-sports centre, 10 miles (16 km) north-northeast of Boise, which is the forest headquarters. Set up in 1908, the forest has an area of 4,140 square miles (10,722 square km).