Sweet Grass County Court is also known formally as Sweet Grass District Court and is in Montana's Sixth judicial circuit.

Although Captain William Clark led a group of men into sweet Grass county around 1806; it wasn't until over 70 years later and the Northern Pacific Railroad lines were laid in this part of the county that Big Timber, which was originally known as Dornix, was founded. At first a railroad station was built at Dornix, the small settlement where the Boulder and Yellowstone rivers met and the only economy in town consisted of a saw mill. A few years after the arrival in the area of a large herd of sheep from California, around 1880, the first woolen mill in Montana was built in Big Timber. The films A River Runs Through It and The Horse Whisperer were filmed in Big Timber portraying the beauty of the area to the world.