In 1804, Lewis and Clark reported the presence of many saltwater springs in the area that now comprises Howard, Cooper, and Saline counties. The largest of these salt springs was the Boone's Lick. The area around this spring was ideal for settlement and for many years "Boone's Lick Country" was a primary destination for pioneers moving west. Nathan and Daniel Morgan Boone, sons of famous frontiersman Daniel Boone, formed a partnership with James and Jesse Morrison in 1805 to produce salt. Brine water was poured into iron kettles and heated to boiling on a stone furnace. As the water evaporated, salt crystallized in the bottom of the kettle. The salt was shipped by keelboat on the Missouri River to St. Louis. Salt, which was indispensable at the time for preserving meat and tanning hides, was produced at the site until approximately 1833. Today, the 52-acre site features picnic facilities and a short trail that winds its way to the spring site, where wood remnants of the salt works and an iron kettle are still visible. Outdoor exhibits interpret this unique saltwater environment and center of frontier industry. Artifacts from the salt manufacturing industry were excavated at the site, and some are on display at the Arrow Rock State Historic Site visitor center in Arrow Rock.

The site offers exhibits and occasional recreational and educational events.

Cape Disappointment State Park is a 1,882-acre camping park on the Long Beach Peninsula, fronted by the Pacific Ocean. The park offers 27 miles of ocean beach, two lighthouses (the North Head Lighthouse and the Cape Disappointment Lighthouse), the Victorian Colbert House Museum, an interpretive center, and hiking trails. Visitors enjoy beachcombing and exploring the area's rich natural and cultural history. The Lewis and Clark Interpretive Center stands high on the cliffs of the park, 200 feet above the pounding Pacific surf. A series of mural-sized "timeline" panels guides visitors through the westward journey of the Lewis and Clark Expedition using sketches, paintings, photographs, and the words of Corps members themselves. The center also features short film presentations, a gift shop and a glassed-in observation deck with views of the river, headlands, and sea. Additional displays focus on local maritime and military history.

The park offers exhibits, tours, and occasional recreational and educational events.

This park encompasses the confluence of the Jefferson, Madison, and Gallatin Rivers. Lewis and Clark anticipated this important headwaters all the way up the Missouri River. An easy three-mile drive off Interstate 90 at Three Forks, this undeveloped park provides outdoor interpretive signs, picnic spots, short hiking trails, a small campground, and—just as the Corps of Discovery found—plenty of mosquitoes!

The site offers occasional recreational and educational events.