The Bob Marshall Wilderness consists of 1,009,356 acres and is contained entirely within Montana. It is part of a wilderness complex that includes the Great Bear Wilderness, the Scapegoat Wilderness and the Bob Marshall Wilderness. Together they total about 1.5 million acres, the third-largest federally protected wilderness area in the nation.

The Bob Marshall Wilderness, which is said to have the largest grizzly bear population outside of Alaska, was named for the preservation pioneer, writer and Wilderness Society co-founder Bob Marshall (1901-1939), the son of the constitutional lawyer and conservationist Louis Marshall.

At a young age, the younger Marshall became fascinated with the outdoors and wilderness travel. He regularly hiked and climbed in the Adirondack Mountains, and also traveled to Alaska.

Marshall earned a doctorate in plant physiology and became independently wealthy after the death of his father. He served as chief of forestry for the Bureau of Indian Affairs and head of recreation management for the Forest Service, and considered wilderness preservation important not only to the environment, but to society.

Marshall largely funded the Wilderness Society in its early years.

Between 1931 and 1934, the Bob Marshall Wilderness was set aside as the South Fork, Pentagon and Sun River Primitive Areas, before being designated a federal wilderness in 1964.

Among its noted geologic features is the “Chinese Wall,’’ a huge escarpment that is part of the Continental Divide. The wall rises straight up more than 1,000 feet for about 22 miles.

Bob Marshall died of heart failure at age 38.