Editor's note: David and Kay Scott this summer are living what many of us wish we could do: they're following a meandering path across the country to visit units of the National Park System. This installment of their trek comes from North Dakota, where they're following the Lewis and Clark National Historic Trail.

Greetings from Bismark, the capital of North Dakota, one of our country’s few economically vibrant states. A low unemployment rate (4.1%), a state budget surplus ($800 million over two years), and an optimistic outlook; that’s what comes with a limited population sitting atop loads of coal, oil, and natural gas.

Perhaps part of the upbeat attitude comes from being able to drive through huge fields of bright sunflowers. It certainly brightened our day as we negotiated the highways of western North Dakota that are filled with trucks involved in the oil industry.

The western Dakotas, both North and South, provide travelers with beautiful scenery. The Black Hills and Badlands of western South Dakota are well-known. However, the lesser-visited badlands of North Dakota, while not as rugged, are equally beautiful. Theodore Roosevelt National Park, especially the north unit, has been one of our favorite units of the National Park System since we first visited many years ago.

Our last email was from Havre, Montana, where winter temperatures fall to 30 and 40 below zero and people still don't complain much. Leaving Havre on Sunday morning, we drove east on U.S. Highway 2 that spans the northern United States. Sunday night we pulled into the small town of Culbertson in far eastern Montana, where we camped in the city park.

Lots of grass, clean restrooms, no charge, but hoards of mosquitoes. Perhaps this is to allow us to gain a better appreciation for why Lewis & Clark continually complained about these pesky insects. Burlington Northern Santa Fe freight trains roared through the night with horns blaring just south of the park. Neither of us remember the noise of the train prior to getting into the tent for the night.

We drove most of Sunday so that we could get near Fort Union Trading Post National Historic Site that we planned to visit the next day. Fort Union is near the confluence of the Missouri and Yellowstone rivers, a prime location for a trading post. In fact, this location was noted by Lewis & Clark when the Corps of Discovery explored the confluence during their 1805 outbound trip.

Fort Union was constructed in the late 1820s and dominated fur trade on the Upper Missouri for nearly 40 years. The reconstructed fort on the location of the original includes the palisade walls, an Indian trade house, two bastions, and the bourgeois house that serves as the visitor center. A fur press is outside the front gate. The national historic site straddles the Montana-North Dakota state line with the fort in North Dakota and the parking lot in Montana.

A ranger at the site indicated the fort typically welcomes from 12,000 to 15,000 visitors per year. The busiest time is during the annual rendezvous that takes places each Father’s Day weekend. This is a special occasion when many visitors wear period dress and bring goods to trade.

This was our third visit to Fort Union Trading Post and we found it just as educational and fun as our first visit many years ago prior to the reconstruction of fort.

Upon departing Fort Union, we drove to the nearby Missouri-Yellowstone Confluence Interpretive Center. Here we walked out back to gain a view of this important location on the Lewis & Clark Trail where the two explorers were to meet during their return to St. Louis. The two had taken different paths at Traveler’s Rest in western Montana.

Following the visit to Confluence Interpretive Center we drove south and then east where we camped at a Corps of Engineers facility on Lake Sakakawea (The spelling of her name keeps changing as we move to different places.), a large body of water created by Garrison Dam on the Missouri River. This proved to be an attractive campground with lots of trees and grass, but few mid-week campers. Perfect for two people who had been kept awake most of the prior night by freight trains.

The following morning we drove a short distance to Knife River Indian Villages National Historic Site. This area was occupied for more than 10,000 years, most recently by the Hidatsa and Mandan Indians who welcomed the Corps of Discovery on May 14, 1804. Near here is where the Corps spent the winter of 1804-05. It is also the place where Lewis & Clark met Charbonneau and his Shoshone wife, Sakakawea. Both were dropped off here in 1806 during the return of the Corps to St. Louis.

The visitor center offers an informative video about Indian life here and a reconstructed earth lodge is just outside. A trail leads past several of the ancient Indian villages where multiple depressions remain from the collapsed earth lodges. Like many other Indian nations, a smallpox epidemic proved a disaster for the Mandan and Hidatsa.

Our next stop was the North Dakota Lewis & Clark Interpretive Center just outside Washburn, North Dakota. The center contains displays that provide insight into the trip by Lewis & Clark. The same admission fee allows entrance to a reconstruction of Fort Mandan, Lewis & Clark’s winter home. The original fort had burned by the time the Corps returned here in 1806. The reconstructed fort is near, but not at the exact location of the original fort. It was fun to compare this three-sided fort to Fort Clatsop, their home during the following winter.

We are preparing to leave Bismark and follow the Missouri into South Dakota, where we are likely to spent the night just north of the capital of Pierre. There is another Corps of Engineers dam and campground where white-haired citizens with a senior pass stay for half price. What a great life.

David and Kay Scott are regular contributors to the Traveler. Their book, The Complete Guide to the National Park Lodges was first published by the Globe Pequot Press in 1997 and is now in its sixth edition.