Boise's Backyard — Idaho's Central Wilderness
Boise National Forest was established on July 1, 1908 by President Theodore Roosevelt — carved from portions of the original Sawtooth, Payette, and Weiser Forest Reserves to protect timber and watershed resources in southwestern Idaho. The forest was named for the Boise River, whose name derives from the French word for "wooded" — fitting for a landscape dominated by ponderosa pine.
Today it encompasses 2,203,703 proclaimed acres across six Idaho counties — Ada, Boise, Elmore, Gem, Valley, and Washington — making it one of the largest national forests in the American West. The forest stretches from the high-desert foothills of the Snake River Plain at roughly 2,800 feet to the granite peaks of the Boise Mountains at 9,730 feet on Steel Mountain. The USFS homepage describes it as spanning "North Fork Payette River Canyon at 2,800 feet in elevation to the nearly 10,000 foot peak of Trinity Mountain."
The geological foundation is the Idaho Batholith — specifically the Atlanta Lobe, a Cretaceous-Paleogene mass of granite and granodiorite covering over 9,700 square miles across Idaho and Montana. This batholith forms the forest's Boise, Salmon River, and West mountain ranges. It is geographically distinct from the Bitterroot Lobe to the north. More than 9,600 miles of streams and rivers and 250+ lakes and reservoirs flow through its terrain — one of the most water-rich national forests in the lower 48. Wikipedia →
Idaho City Ranger District: 3833 Highway 21, Idaho City, ID 83631 · 208-392-3700 · Mon–Fri 8am–4:30pm
Official Site: fs.usda.gov/r04/boise
From Long Valley to the High Desert
Each district manages a distinct landscape — from the world-class kayaking of the North Fork Payette to the geothermal corridors of Highway 21. Together they cover over 2.2 million acres of Idaho's most accessible backcountry.
Two of America's Greatest Wilderness Areas
Boise National Forest hosts portions of both the largest and most iconic designated wilderness areas in Idaho — one to its north and one to its east. No other national forest in the lower 48 borders both simultaneously.