Uthriem Roliri, Brotherhood of the Forest in the Sindarin tongue, is a covert brotherhood of human woodsmen intent on protecting the wilderness and its wildlife. The group was founded by followers of Siem in the foothills of the Sorkin Mountains in the second century TR as a reaction to the depredations committed by gargun.

The Uthriem Roliri exists only on Hârn. The Brotherhood rarely has more than 200 members, preferring to remain a small and elite group. Although still concentrated in eastern Hârn, the Brothers can be found in most frontier or wilderness areas, especially where gargun live near human settlements.