HD 425 covers the upper Tongue River country in southeast Montana—the river corridor from the Wyoming border running north toward Birney and Ashland, with the Custer NF Ashland District timber on the west and the Tongue River breaks rising on both sides. Elevations run from about 2,800 feet on the Tongue River bottom to 4,000 feet on the higher pine-covered ridges. The country is the textbook southeast Montana mosaic: ponderosa pine and Rocky Mountain juniper on the timbered breaks, sandstone outcrops, sage-and-grass benches, big rolling pine ridges, and cottonwood-and-willow corridors along the Tongue River. The Tongue River Reservoir at the south end of the unit (just north of the Wyoming line) anchors a small recreation area. Mule deer use the timbered breaks and rocky benches in real numbers—425 has a deserved reputation for trophy-class mulies—and whitetail concentrate in the river bottoms; elk live the timber in surprising numbers; turkeys in the pines. Custer Gallatin NF (Ashland District) on the western fringe, BLM scattered through, DNRC state sections, and significant private ranchland (some of the bigger SE MT cattle outfits). Block Management is essential. MT-314 (the Tongue River Road) is the principal paved access running north-south; a network of county and forest dirt routes handles the rest. Birney is a tiny outpost—essentially nothing but the school and a few houses. Ashland is north up the road. Sheridan, WY is south just over the border with full services. Cell service is essentially gone. Roads gumbo when wet. The mule-deer hunt on Block Management ground or the public Forest Service timber is one of the better SE MT opportunities for a hunter who'll walk away from the truck.