(MONEY Magazine) – In 1799, 12-year-old Conrad Reed was wandering down by a creek on his family's North Carolina farm when he found a large yellow rock. He'd never seen anything like it, and neither had his father, John Reed, who used the 17-pound stone as a doorstop for three years before he realized what it was: gold.

America's gold history is usually associated with California, but the Reed nugget--discovered 50 years before the California gold rush of 1849--was the first documented gold find in the United States. It set off a mini-rush in North Carolina's Piedmont region and gave rise to a local gold economy so large and dynamic that the federal government opened a branch of the U.S. Mint in nearby Charlotte in 1837. And although nobody realized it at the time, the Reed strike was also the beginning of what has become one of the area's most interesting tourist attractions: the Reed Gold Mine State Historic Site (9621 Reed Mine Rd., Stanfield, N.C.; 704-721-4653), offering one of several underground mine tours scattered around the country in a sort of loose network of subterranean tourism (see "Mines, all mines" on page 154).

John Reed began mining operations on his property in 1803. He died in 1845, but work carried on until 1912, after which the site lay dormant for decades. Ownership eventually passed to the State of North Carolina, which restored the property and opened it to the public in 1977. Today, a visit to the mine is a trip back in time--not just to the days when North Carolina was known as the Gold State but to an era when miners routinely descended beneath the earth's surface and used their hands to do work that is now done by modern machines. You can get a firsthand sense of what this was like by taking a wonderful (and free) 45-minute walking tour of one of the mine tunnels, which goes down about 60 feet below the surface.

The guided tour takes several twists and turns through a series of crude tunnels. The temperature, as in most underground mines, holds steady at about 50[degrees]F and the air starts getting a bit damp as you move down toward the water table, but on the whole the route is easy and comfortable to navigate. There are several displays of old mining equipment, and in the tunnel's rough-hewn walls you can see the veins of white quartz that contained the precious metal. As the tour guides make clear, gold mining was no picnic--between cave-ins, blasting accidents, drilling accidents and so on, miners were constantly at risk. (Present-day visitors need not worry--the tunnel is well lit and equipped with new support beams.)

The claustrophobic or squeamish can opt for several aboveground attractions, including a series of excellent exhibits on the region's gold history, displays of ore-crushing machinery and even the chance to pan for gold in the stream where the first nugget was found. Special programs and exhibits are on tap this summer to celebrate the bicentennial of Conrad Reed's discovery. It all amounts to a tremendously instructive primer on a little-known chapter of history.

Mining is an industry that tends to have a particularly broad influence across an area's social and economic fabric. Learning about a given mining operation, therefore, is often an excellent way to learn about regional history. A fantastic example of this can be found in Scranton, Pa. at the Lackawanna Coal Mine (in McDade Park, off Keyser Avenue, exit 38 on the Pennsylvania Turnpike or exit 57B on I-81; 570-963-6463).

Visitors to the Lackawanna site ($6; $4 for kids) ride down 300 feet into the mine's depths aboard the same kind of railcar that the miners once used. From there you walk through an astonishing latticework of cavernous tunnels and shafts. The tour guides, all former coal miners, do a great job of outlining the technical, geological and physical challenges presented by coal mining and explain how the industry shaped the local culture. This part of the story is explored in greater detail at the Anthracite Heritage Museum (570-963-4804), which is situated adjacent to the mine and has exhibits on subjects like the immigrants who settled in the area to work the mines, the textile mills where women labored while their husbands were digging for coal and the stormy history of labor strife caused by the coal companies' ruthless employment policies. This is one of America's best regional history museums and a perfect complement to the mine tour.

Yet another underground tour is available on the Keweenaw Peninsula, a little talon of land projecting from the northwestern shore of Michigan's Upper Peninsula. Although most of Northern Michigan's mining heritage revolves around iron, as town names like Ironton, Iron Mountain and Iron River attest, the Keweenaw was copper territory, and this is where you'll find the Delaware Copper Mine (U.S. Highway 41, Delaware, Mich.; 906-289-4688). Unlike the Reed and Lackawanna facilities, both of which are municipally owned, this is a mom-and-pop operation: The mine, which was active from 1847 to 1887, is run by Tom and Lani Poynter, who bought the abandoned site in 1977, restored it and turned it into a first-rate attraction.

The Delaware mine tour ($8; $4 for kids) goes down about 110 feet and is traversed entirely on foot. In the spring and fall, you can take a short, self-guided tour of the well-lit tunnels; in the summer, guides lead 45-minute tours. As you walk through the tunnels, you'll see veins of copper clearly visible in the surrounding walls, as well as excellent displays describing the mining process. Topside attractions include old mining equipment, trails past abandoned mine buildings dating back to 1870 and a chance to search the grounds for copper souvenirs.

All three of these mine tours create the lasting impression that mining was difficult, dangerous work. Indeed, as some miners liked to joke, "You'd have to have a hole in your head to work in a hole in the ground." Happily, no such prerequisite is needed to enjoy these fascinating places today.

Award-winning travel writer Paul Lukas currently has no plans to tour a uranium mine.