“She Who Watches,” a 10,000-year-old Native American petroglyph, is the main attraction for visitors to Horsethief Lake State Park (509-767-1159), located 15 miles west of Maryhill. Lewis and Clark mentioned the 8-by-6-foot carving in their journals.

Lewis and Clark noted several new species of birds and plants around Maryhill State Park, west of the Tri-Cities between Hwy. 12 and SR 14. The park features several scenic nature trails.

The Maryhill Museum of Art (509-773-3733) sits atop the rugged banks of the Columbia River overlooking several campsites where the explorers slept. It houses several Lewis and Clark artifacts, including two of President Jefferson's peace medals (only 5 of 56 originals exist) the explorers carried with them, American Indian basketry, and maps and journals. Open March through November.