A MOUNTAIN of wheat arises in Lewiston, Idaho’s inland port, waiting to be shipped out to the world.

Lewiston is far from the Pacific Ocean and the big ports of the West Coast — about 465 miles up the Columbia and Snake rivers.

But grains and goods flow from and to the Idaho city by big cargo ships, past its neighbor (and small port) of Clarkston, Wash.

The two towns are named in honor of the 19th-century explorers Lewis and Clark, who traveled across what’s now the western United States to the Pacific Coast.

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In the last part of their arduous, daring journey, Lewis and Clark paddled (and portaged) in dugout canoes along the Columbia and Snake, then free-flowing and wild rivers. Now massive dams and towns, ships and boats, and amber piles of grain have transformed the land and riverscape.

Kristin R. Jackson is The Seattle Times NWTraveler editor. Contact her at kjackson@seattletimes.com.