Southeastern Montana is the most “Western” of Montana’s regions. Historically, it is the West of the early trapper and hunter and of the clash between Indian and infantry. It was the Montana of the cattle drover and the great cattle barons.
Today, it is still home to thousands of American Indians, and it is still unashamedly cowboy country.
However, in times gone by, all this land was once beachfront property. It’s hard to believe, looking at the dry and dusty buttes and rolling prairies of southeastern Montana, that amphibious dinosaurs and palm trees were once native to this area.
For millions of years this was the shoreline of vast inland seas. Southeastern Montana’s most distinctive geologic formations—badlands, prairies, and sandstone bluffs, as well as the coal and oil they mask—all date from a primeval maritime past.
The Yellowstone River is the locus of the entire region. As the river moves eastward through the prairies, it picks up the waters of three major southerly tributaries: the Bighorn, the Tongue, and the Powder. As it discharges into the Missouri, the Yellowstone is the largest free-flowing river in the United States.
As the principal avenue of entry and exit in Montana during the pioneer days, the Yellowstone took out the region’s wealth of furs, brought in soldiers, and transported cattle and sheep to eastern markets.
Towns like Miles City, Glendive, and Billings  grew up on its banks as railroads extended up the valley. Within memory, ranchers on the “North Side,” up to Jordan country, and on the “South Side,” down the Powder River, trailed livestock to the “Valley.” In these river towns, they partied, visited, and stocked up on groceries before heading out to their far-flung ranches.
The dominant social unit in southeastern Montana today is still the working ranch and family farm, and the same Yellowstone Valley towns are still the center of trade, shopping, and social life.
This is about as real as the West gets, but it’s not a Western theme park.
Today, cowboys are stockmen, Indians are Native Americans, and the spirit of the Wild West has grown up into agribusiness. Southeastern Montana is not a highly developed tourist destination, but for the traveler with patience, a sense of humor, and an interest in wildlife, pristine landscapes, Native America, and the lore of the West, this corner of Montana has few equals.
Billings  has the largest airport in Montana, with service from Delta (SkyWest), United, Alaska/Horizon, and Northwest.
You’ll need an automobile to travel off the interstate in southeastern Montana.
Rimrock Stages (800/255-7655, www.rimrocktrailways.com ) offers once-daily east-west service to the major towns along I-94 and south toward Denver on I-90.