Cape Disappointment is a large headland forming the northern portion of the mouth of the Columbia River, as it opens to the Pacific Ocean. Most members of the Corps of Discovery arrived in this area where they were first able to glimpse the ocean on November 15, 1805, and set up a base camp near Chinook Point. However, Lewis and a small party of men had set out ahead of the rest of the group the day before and began scouting for a favorable site for a winter encampment.