Question: The Bridger Trail, also known as the Bridger Road and Bridger Immigrant Road, was an overland route connecting the Oregon Trail to the gold fields of Montana, Gold was discovered in Virginia City, in 1863, Virginia City is a town in, and the county seat of which county in Montana, United States?

full_context: Document 1: Confederate Gulch and Diamond City: Confederate Gulch is a steeply incised valley on the west facing slopes of the Big Belt Mountains in the U.S. state of Montana. Its small stream drains westward into Canyon Ferry Lake, on the upper Missouri River Valley near present-day Townsend, Montana. In 1864 Confederate soldiers on parole from the American Civil War made a minor gold discovery in the gulch, but in 1865 the discovery of the sensationally rich Montana Bar—one of the richest placer strikes per acre ever made—led to other rich gold strikes up and down the gulch, and touched off a frantic boom period of placer gold mining that extended through 1869. From 1866 to 1869 the gulch equaled or outstripped all other Montana Territory mining camps in gold production, producing an estimated $19 to $30 million in gold—late 1860s money. For a time, the gulch became the largest community in Montana—in 1866 Montana had a total population of 28,000, and of these, about 10,000 (35%) were working in Confederate Gulch. The main community was Diamond City , and while gold production was at its height, Diamond City roared along both night and day. During its heyday, Diamond City was the county seat of Montana's Meagher County, although today the area has become part of Broadwater County. In their frantic efforts to get at more gold, the miners built ditches and flumes that extended for miles, and employed high pressure hydraulic mining methods which washed down whole hillsides and ate up the gulch floor. The hydraulic mining process stripped the gulch and left huge spoil banks—hydraulic mining even consumed the site of Diamond City, which had to be moved to a new location. Then the gold ran out, the boom was over and the population simply picked up and left. In 1870 there were only 255 people left and a year later only about 60. Today hardly a trace remains of Diamond City or the other gulch communities. The gulch is quiet and empty, with only an occasional summer prospector, or a rare traveler using the unimproved road that still winds up the gulch from the Missouri Valley and crosses the top of the Big Belts on its way down to the Smith River Valley. Diamond City, Confederate Gulch and the Montana Bar were spectacular examples of the flash-in-the pan Montana placer gold mining camps, but what a flash.
Document 2: Bridger Trail: The Bridger Trail, also known as the Bridger Road and Bridger Immigrant Road, was an overland route connecting the Oregon Trail to the gold fields of Montana. Gold was discovered in Virginia City, Montana in 1863, prompting settlers and prospectors to find a trail to travel from central Wyoming to Montana. In 1863, John Bozeman and John Jacobs scouted the Bozeman Trail, which was a direct route to the Montana gold fields through the Powder River Country. At the time the region was controlled by the Sioux, Cheyenne and Arapaho, who stepped up their raids in response to the stream of settlers along the trail.
Document 3: Bad Pass Trail: The Bad Pass Trail, also known as the Sioux Trail, was established by Native Americans on the border of present-day Montana and Wyoming as a means of access from the Bighorn Basin in Wyoming to Bison-hunting grounds in the Grapevine Creek area of Montana. Marked by stone cairns, the trail led across Bad Pass and was established in pre-Columbian times. After Europeans arrived in the area it was frequented by fur trappers and mountain men, beginning in 1824. Trappers assembled pack trains at the junction of the Shoshone River and the Bighorn River, using the Bad Pass Trail to avoid Bighorn Canyon. The trail ended at the mouth of Grapevine Creek on the Bighorn, from which the pack train could float down the Bighorn on rafts to the Yellowstone River and then to the Missouri and on to St. Louis.
Document 4: Fort Bridger: Fort Bridger was originally a 19th-century fur trading outpost established in 1842, on Blacks Fork of the Green River, in what is now Uinta County, Wyoming, United States. It became a vital resupply point for wagon trains on the Oregon Trail, California Trail, and Mormon Trail. The Army established a military post here in 1858 during the Utah War, until it was finally closed in 1890. A small town, Fort Bridger, Wyoming, remains near the fort and takes its name from it.
Document 5: Madison, West Virginia: Madison is a city and former coal town in Boone County, West Virginia, United States. The population was 3,076 at the 2010 census. It is the county seat of Boone County.
Document 6: Madison, Indiana: Madison is a city in and the county seat of Jefferson County, Indiana, United States, along the Ohio River. Its estimated population was 12,247 as of 2016. Over 55,000 people live within 15 miles of downtown Madison. Madison is the largest city along the Ohio River between Louisville, Kentucky and Cincinnati, Ohio. Madison is one of the core cities of the Louisville-Elizabethtown-Madison metroplex, an area with a population of approximately 1.5 million. In 2006, the majority of Madison's downtown area was designated the largest contiguous National Historic Landmark in the United States—133 blocks of the downtown area is known as the Madison Historic Landmark District.
Document 7: Hecla, Montana: Hecla was a town in Beaverhead County, Montana. It has been designated as a ghost town with only a few ruined buildings remaining. It was notable at one time as the home of Blanche Lamont, who taught at Hecla's one-room schoolhouse. Lamont would become the first of two murder victims of Theodore Durrant. Margaret Brown also lived there for a time.
Document 8: Virginia, Minnesota: Virginia is a city in Saint Louis County, Minnesota, United States, on the Mesabi Iron Range. The population was 8,712 at the 2010 census. According to a water tower in the middle of town, the city's nickname is the "Queen City", or "Queen City of the North".
Document 9: Bozeman Trail: The Bozeman Trail was an overland route connecting the gold rush territory of Montana to the Oregon Trail. Its most important period was from 1863–68. Despite its name, "the major part of the route in Wyoming used by all Bozeman Trail travelers in 1864 was pioneered by Allen Hurlbut". Many miles of the Bozeman Trail in present Montana followed the tracks of Bridger Trail, opened by Jim Bridger in 1864. The flow of pioneers and settlers through territory of American Indians provoked their resentment and caused attacks. The challengers to the route were newly arrived Lakotas and their Indian allies, the Arapahoe and the Cheyenne. The United States put emphasis on a right to "establish roads, military and other posts" as described in Article 2 in the Fort Laramie Treaty of 1851. All parties in the conflict had signed that treaty. The Crow Indians held the treaty right to the contested area and had called it their homeland for decades. They sided with the whites. The U.S. Army undertook several military campaigns against the hostile Indians to try to control the trail. Because of its association with frontier history and conflict with American Indians, various segments of the trail are listed on the National Register of Historic Places (NRHP).
Document 10: Virginia City, Montana: Virginia City is a town in and the county seat of Madison County, Montana, United States. In 1961 the town and the surrounding area were designated a National Historic Landmark District, the Virginia City Historic District. The population was 190 at the 2010 census.
Document 11: Montana Highway 287: Highway 287 (MT 287) is a state highway in the U.S. state of Montana. The highway runs 42.822 mi from MT 41 in Twin Bridges east to U.S. Route 287 (US 287) in Ennis. MT 287 is the primary east–west highway of Madison County. The highway connects the county's four towns, including Sheridan and the county seat of Virginia City. The course of MT 287 follows the ultimate portions of two trails that met in Virginia City, the center of the Alder Gulch gold rush of the mid-1860s and the second territorial capital of Montana. Parts of the highway were improved from rudimentary roads around 1920 from Virginia City to Ennis. This connection became the first portion of Montana Highway 34 in the early 1930s; the highway was extended west to Twin Bridges in the late 1930s. MT 34 was reconstructed from Twin Bridges through Alder to Virginia City in the late 1930s and early 1940s and between Virginia City and Ennis in the late 1940s to mid-1950s. The MT 287 designation was first applied to a cross-state route from West Yellowstone to Canada in the late 1950s. The highway was rerouted in place of MT 34 in the early 1960s. MT 287 was replaced by US 287 along much of the cross-state corridor in the mid-1960s. The highway extended north of Twin Bridges to Whitehall until the late 1970s, when it achieved its current length.
Document 12: Silver Bow County, Montana: Silver Bow County is a county in the State of Montana. As of the 2010 census, the population was 34,200. Its county seat is Butte. In 1977, the city and county governments consolidated to form the single entity of Butte-Silver Bow. Additionally, the town of Walkerville is a separate municipality from Butte and is within the county.
Document 13: Montana Trail: The Montana Trail was a wagon road that served gold rush towns such as Bannack, Virginia City and later Helena, Montana during the Montana gold rush era of the 1860s and 1870s. Miners and settlers all travelled the trail to try to find better lives in Montana. The trail was also utilized for freighting and shipping supplies and food goods to Montana from Utah. Bandits and Native Americans, as well as the weather, were major risks to travelling on the Montana Trail.
Document 14: Vaughn, Montana: Vaughn is a census-designated place (CDP) in Cascade County, Montana, United States. The population was 658 at the 2010 census. It is part of the Great Falls, Montana Metropolitan Statistical Area. It is named for Montana pioneer Robert Vaughn, whose homestead on the Vaughn Ranch encompassed part of the town.
Document 15: Alder Gulch: Alder Gulch (alternatively called Alder Creek) is a place in the Ruby River valley, in the U.S. state of Montana, where gold was discovered on May 26, 1863 by William Fairweather and a group of men including Barney Hughes, Thomas Cover, Henry Rodgers, Henry Edgar and Bill Sweeney who were returning to the gold fields of Grasshopper Creek, Bannack, Montana. They were on their way to Yellowstone Country from Bannack but were waylaid by a band of Crow Indians. After being ordered out of Crow hunting grounds, they crossed the East Slope of the Tobacco Root Mountains and camped for the night in Elk Park, where William "Bill" Fairweather and Henry Edgar discovered gold, while the remaining party was out hunting for meat. Agreeing to keep the new discovery quiet the group of miners returned to the town of Bannack for supplies. Unfortunately word leaked out about the new strike, and miners followed the Fairweather party out of town. The party stopped at the Point of Rocks, part way between Bannack and Alder Gulch, and established the Fairweather Mining District in a miners meeting. It was agreed that the discoverers were entitled to two claims and first choice. The first stampede of miners reached Alder Gulch June 6, 1863 and the population swelled to over 10,000 in less than 3 months. The "Fourteen Mile City" ran the length of the gulch, and included the towns of Junction City, Adobe Town, Nevada City, Central City, Virginia City, Montana, Bear Town, Highland, Pine Grove French Town, Hungry Hollow, and Summit. Upon arrival the miners lived in brush wickiups, dugouts and under overhanging rocks until cabins could be built. The first structure built in Virginia City was the Mechanical Bakery. Virginia City, and Nevada City were the centers of commerce during the height of the Alder Gulch gold rush. In the first year the area had over 10,000 people living there. Montana Territory was established in May 1864, and the first territorial capital was Bannock. The capital then moved to Virginia City, where it remained until 1875. The Alder Gulch diggings were the richest gold placer deposits ever discovered, and in three years $30,000,000 was taken from them, with $10,000,000 taken out in the first year. Nowadays, except during summertime, the streets of Virginia City are usually quiet and relatively few visitors find their way to the 16 ton granite monument that marks the spot of that incredible discovery of May 26, 1863.
ground_truth: Madison County