When Meriwether Lewis and William Clark led their Corps of Discovery up the wild Missouri River in 1804, they took time to explore on foot the land that eventually became southeastern South Dakota. The Corps found huge herds of pronghorn and bison, grizzly bears and investigated curiosities like Spirit Mound. But what if they ditched the keelboats and walked the land today? They’d find a place dotted with family farms, verdant green fields and lush river valleys. They would explore lots of small towns (and one that’s very, very big). Clark would have a hard time keeping up with journal entries about the diverse wildlife (though the grizzlies are gone) and unique geological features. Yes, they would be amazed — and so will you.