October 17, 1805
Clark explores the Columbia River reaching the mouth of the Yakima River. Lewis records the vocabulary of the Indians living at the Snake and Columbia River confluence at present Sacajawea State Park.
an Indian Showed me the mouth of the river which falls in below a high hill on the Lard. N. 80° W. 8 miles from the Island. The river bending Lard.— This river is remarkably Clear and Crouded with Salmon in maney places