Northwest of Walla Walla at the confluence of the Snake and Columbia Rivers lies Sacajawea State Park and Interpretive Center (509-545-2361), named for the amazing Shoshone Indian who served as Lewis and Clark's interpreter. Interactive exhibits and Native American artifacts are among its offerings. For a schedule of Lewis and Clark programs being offered at Sacajawea and Columbia Hills State Parks, visit www.parks.wa.gov/lewisandclark/events.asp.

A Lewis and Clark Interpretive Sign in Richland marks the Expedition’s furthest point up-river on the Columbia. It’s located at the intersection of Columbia Center Blvd. and Columbia Dr., the first federal highway ever built.

The East Benton County Historical Museum (509-582-7704) in Kennewick focuses on the pioneers who followed Lewis and Clark.

A 200-mile, self-guided “Lewis and Clark Trail Historical Day Tour” includes numerous points of interest within three counties. Call the Tri-Cities Visitor and Convention Bureau (800-254-5824) for maps.

Columbia River Journeys (509-943-0231) offers interpretive boat tours following the Corps of Discovery’s path down the Snake and Columbia Rivers. Tours run daily April through October.