Start, as they did, in the eastern part of the state, along the Missouri River at Fort Union, a fascinating re-creation of an 1840s frontier trading post at the confluence of the Missouri and Yellowstone Rivers, and head west along Highway 2, following the Missouri to Fort Peck, about 120 miles west of the North Dakota line.

Spend the first night at Fort Peck, with its enormous reservoir, dinosaur museum, and 1930s New Deal architecture, including a well-preserved hotel from the town’s dam-building heyday. West and north of Fort Peck, Highway 2 follows the Milk River, named by Meriwether Lewis for the color of its water.

From Fort Peck to Havre is about 160 miles, then it’s another 50 miles south on Highway 87 to Virgelle, where you’ll rejoin the Missouri and head about 25 miles south to Fort Benton.

A real highlight of a Lewis and Clark pilgrimage is to take a boat trip through the wild and scenic stretch of the Missouri where the corps saw “seens of visionary inchantment.” Road travelers can drive the Missouri Breaks Backcountry Byway.

The great waterfalls of the Missouri meant many days of portaging for the corps members; for travelers, Great Falls, 36 miles southwest of Fort Benton via Highway 87, is the site of the excellent Lewis and Clark National Historic Trail Interpretive Center.