The Challis forest is broken up into five pieces separated into two main sections. In total, it is 125 miles wide east to west and ninety-two miles long.

Within the Lost River Range is Borah Peak, Idaho's highest point at 12,662 feet. Also within the forest is the Middle Fork of the Salmon River at 3,790 feet.

More than 1,600 miles of trails crisscross the Challis forest. Two of these, the Knapp Creek-Loon Creek Trail and the Mill Creek Lake Trail, are designated National Recreation Trails.

For the car camper, the forest has twenty-six primary, developed campgrounds featuring 260 campsites. The campgrounds offer a variety of activities. For those hoping to escape society for a few days up to a few weeks, primitive camping is allowed throughout the forest for free.

Near Pole Flat, visitors can wander among the ruins of the ghost towns of Custer and Bonanza. Boundary Creek is the jumping-off point for floating the Middle Fork of the Salmon River. Mill Creek is a family picnic spot, while hunting and high-mountain fishing are the attractions at Starhope.

Among the more controversial parts of the forest are the more than thirty miles of designated off-road-vehicle trails in the Lost River District.

Salmon Forest Overview
Salmon is Idaho's most remote and undeveloped national forest. To give a bit of perspective, it is located 150 miles by highway from any good-sized city, such as Missoula, Montana, or Idaho Falls.

The forest's 1.8 million acres are governed by a harsh Alpine climate and a short growing season. The geology of the area is responsible for unstable soils and dramatic relief. It also provides an extraordinary amount of ideal stream habitat for steelhead and anadromous salmon spawning. Mule deer, antelope, moose, bears, elk, bighorn sheep, and mountain goats are some of the more prominent wildlife here.

The Frank Church River of No Return Wilderness Area is partially within the Salmon forest. The Salmon River, called the River of No Return by pioneers, courses ninety-seven miles through the wilderness and is essentially the only major access. The wilderness, established in 1980, contains 2.36 million acres and is just slightly larger than Yellowstone National Park. Today the roiling white water that claimed so many early floaters beckons white-water enthusiasts from around the world.

Half of the forest's 1,200 miles of trails are in the wilderness. The Salmon Forest includes several nationally designated trails, such as the Continental Divide National Scenic Trail, Lewis and Clark National Historic Trail, Nez Perce National Historic Trail, Divide-Twin Creek National Recreation Trail, and Bear Valley National Recreation Trail. Only ten primary, developed campgrounds with 142 family units are located within the forest, although there are many primitive camps.

For the Alpine skier, the modest Lost Trail Ski Area, near Gibbonsville close to the Idaho-Montana border, features a day lodge, 1,200 feet of vertical drop, and eighteen runs. The runs are served by two chairlifts and two rope tows.