Bull River Guard Station, also called Bull River Ranger Station, is a historic Forest Service site in the Kootenai National Forest of northwestern Montana. Established in 1907 on the Bull River near its meeting with the East Fork Bull River, it reflects the early years of federal forest administration in the region. Its main office and residence, built in 1908, is a one-and-a-half-story log building on a concrete wall foundation, designed for a remote ranger outpost. Constructed by Granville “Granny” Gordon, one of Theodore Roosevelt’s early “instant rangers,” it survives as an important example of early Forest Service development in Montana and was listed on the National Register of Historic Places in 1990.