HD 317 takes in the country around Three Forks—the broad ag valley where the Jefferson, Madison, and Gallatin rivers come together to form the Missouri, with the Tobacco Root foothills rising on the west and the Horseshoe Hills running northeast. Elevations span 4,000 feet on the river bottoms to about 8,000 feet on the higher Tobacco Root foothill ridges and the Horseshoe Hills crest. The valley floor is irrigated hay, alfalfa, and pasture, with cottonwood-and-willow river corridors that hold whitetail in respectable numbers. The Horseshoe Hills are open Douglas fir and limber pine parkland with rocky outcrops, sage benches, and grass—classic mid-elevation Montana mule deer country. The Tobacco Root foothills climb through ponderosa and Douglas fir into denser timber and eventually alpine country in HD 340 to the south. Mule deer are the headline animal—317 has produced respectable bucks for decades—plus pronghorn on the open valley flats and a healthy whitetail population in the bottoms. Land ownership is mostly private valley floor with BLM and DNRC state sections scattered through the Horseshoe Hills and the Tobacco Root foothills. I-90 cuts the unit east-west, with US-287 climbing north and county roads gridding the valley. Three Forks is small but has gas, the Sacajawea Hotel, a couple of cafes, basic groceries; Bozeman is 30 minutes east, Butte 60 west. Cell service holds along I-90 and US-287. Block Management is genuinely critical here—the BMA enrollments around Three Forks are some of the more popular in the state and they fill up. The public ground in the Horseshoe Hills is walkable and underused. Pronghorn opener can be productive on the BLM and state sections south of Manhattan.