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?

Context paragraphs:
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.

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.

Lysite, Wyoming: Lysite (also Lysaght) is an unincorporated community in northeastern Fremont County, Wyoming, United States.  It lies along local roads northeast of the city of Lander, the county seat of Fremont County.  Its elevation is 5,276 feet (1,608 m).  Although Lysite is unincorporated, it has a post office, with the ZIP code of 82642.  The Bridger Trail passed near Lysite on its way north to the gold fields of Montana in the 19th century.

Department of the Platte: The Department of the Platte was a military administrative district established by the U.S. Army on March 5, 1866, with boundaries encompassing Iowa, Nebraska, Dakota Territory, Utah Territory and a small portion of Idaho.  With headquarters in Omaha, the district commander oversaw the army's role initially along the Overland route (or Oregon Trail) to Salt Lake City, then later the construction route of the Union Pacific Railroad.  The district also included the Montana road (or Bozeman Trail) through eastern Wyoming.  The district was discontinued when the Army's command was reorganized in 1898.

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.

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.

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.

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).

Overland Trail: The Overland Trail (also known as the Overland Stage Line) was a stagecoach and wagon trail in the American West during the 19th century.  While portions of the route had been used by explorers and trappers since the 1820s, the Overland Trail was most heavily used in the 1860s as an alternative route to the Oregon, California, and Mormon trails through central Wyoming.  The Overland Trail was famously used by the Overland Stage Company owned by Ben Holladay to run mail and passengers to Salt Lake City, Utah, via stagecoaches in the early 1860s.  Starting from Atchison, Kansas, the trail descended into Colorado before looping back up to southern Wyoming and rejoining the Oregon Trail at Fort Bridger.  The stage line operated until 1869 when the completion of the First Transcontinental Railroad eliminated the need for mail service via Thais' stagecoach.  Mostly used during the gold rush of 1848.

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.

Supporting paragraphs: Bridger Trail Virginia City, Montana
Answer: Madison County