43 U.S.C. § 1063

No person, by force, threats, intimidation, or by any fencing or inclosing, or any other unlawful means, shall prevent or obstruct, or shall combine and confederate with others to prevent or obstruct, any person from peaceably entering upon or establishing a settlement or residence on any tract of public land subject to settlement or entry under the public land laws of the United States, or shall prevent or obstruct free passage or transit over or through the public lands: Provided , This section shall not be held to affect the right or title of persons, who have gone upon, improved, or occupied said lands under the land laws of the United States, claiming title thereto, in good faith.