YANKTON, South Dakota — What is now the southeast corner of South Dakota doesn’t look anything like it did when Lewis and Clark came through in 1804 and 1806.

On a map, the sliver of land, bounded by the Missouri and Big Sioux rivers, still resembles a little beard growing off the chin of the square-faced state. But Lewis and Clark didn’t have maps.

And today, the Missouri has been forever changed by a half-dozen dams built in the last century for flood control, water supply and power production.

Yankton, the old capital of the Dakota Territory, is just downriver from the site of the Gavins Point Dam.

The dam is the site of a large park and campground. Although its namesakes wouldn’t recognize its location, it’s also the site of the Lewis and Clark Visitor Center atop Calumet Bluff above the dam. The center, operated by the U.S. Army Corps of Engineers, includes wildlife displays, an early history of the river, Lewis and Clark exhibits, and a great view of the dam.

Yankton, itself, has a beautiful downtown riverfront park, which also is the site of a reproduction of the Dakota Territorial Capitol, a simple, two-story wood-frame structure that belies the tumultuous politics — and politicians — it housed in Dakota’s early days, more than a half-century after the explorers came through.

A new museum and cultural complex also is scheduled to open in Yankton on Dec 15. The Mead Cultural Education Center, located in a historic 1909 mansion, will house the Dakota Territorial Museum with exhibits about Lewis and Clark, Dakota’s territorial days and more.

As Yankton’s museum opens, a widely heralded museum in nearby Vermillion will be closing, temporarily. Visitors have just a few weeks to explore the National Music Museum before the doors shut Oct. 6.

The remarkable museum, on the pretty campus of the University of South Dakota, has outgrown its home in Vermillion’s historic Carnegie Library and will undergo a major renovation, including an additional 4,600 square feet of exhibit space. The museum is scheduled to reopen in 2021.

Travelers who can squeeze in a visit, or put it off for a few years, will see a world-class collection of musical instruments from around the world and throughout history. Among the 1,500 instruments on display are the earliest-existing French grand piano, a unique collection of early Italian stringed instruments — including one of two existing Stradivari mandolins — and one of the best collections of 19th and early 20th century American band instruments.

Travelers seeking a place to stay will find a lot better accommodations than did Lewis and Clark. Valiant Vineyards in Vermillion, South Dakota’s oldest winery, offers comfortable guest rooms with beautiful views of the Vermillion River Valley. The wine is good, too, including an interesting and unusual vintage made with wild vitis riparia grapes, the same grape that Clark, in his journal, called “the best largest grapes I ever tasted.”

For more information about South Dakota travel, call 1-800-732-5682 or visit travelsouthdakota.com.

— Steve Stephens can be reached at sstephens@dispatch.com or on Twitter @SteveStephens.