Rock Fort was an important mid-Columbia campsite for the Lewis and Clark Expedition. After a portage around the Great Falls (Celilo), the expedition came to a gentle part of the river near the present city of The Dalles and formed camp on a high point of rocks that made “a kind of fortification well calculated for defense.” The expedition remained there October 25, 26, and 27, 1805, drying supplies, repairing canoes, hunting, and reconnoitering the river below. On the return journey, the party came back to the camp on April 15, 1806, to the place Lewis called “Rock Fort Camp.”