The Gates of the Mountains Wilderness is located in the U.S. state of Montana. Created by an act of Congress in 1964, the wilderness is managed by Helena National Forest. A day use campground near the Gates of the Mountains, Meriwether Picnic site, is named in honor of Meriwether Lewis. Gates of the Mountains Wilderness (then known as the Gates of the Mountains Wild Area) was the site of the 1949 Mann Gulch fire, which claimed the lives of 13 firefighters and which was the subject of Norman Maclean's book Young Men and Fire.