What is now Cannon Beach, as well as the coastal area surrounding it, is part of the traditional territory of the Tillamook tribe.

William Clark, one of the leaders of the Lewis and Clark Expedition, journeyed to Cannon Beach in early 1805. The expedition was wintering at Fort Clatsop, roughly 20 miles (32 km) to the north near the mouth of the Columbia River. In December 1805, two members of the expedition returned to camp with blubber from a whale that had beached several miles south, near the mouth of Ecola Creek. Clark later explored the region himself.[7] From a spot near the western cliffs of the headland he saw "...the grandest and most pleasing prospects which my eyes ever surveyed, in front of a boundless Ocean..." That viewpoint, later dubbed "Clark's Point of View," can be accessed by a hiking trail from Indian Beach in Ecola State Park.

Clark and several of his companions, including Sacagawea, completed a three-day journey on January 10, 1806, to the site of the beached whale. They encountered a group of Native Americans from the Tillamook tribe who were boiling blubber for storage. Clark and his party met with them and successfully bartered for 300 pounds (136 kg) of blubber and some whale oil before returning to Fort Clatsop.[8] There is a wooden whale sculpture commemorating the encounter between Clark's group and the Tillamooks in a small park at the northern end of Hemlock Street.[9]

Clark applied the name "Ekoli" to what is now Ecola Creek.[10] Ehkoli is a Chinook word for "whale".[10] Early settlers later renamed the creek "Elk Creek", and a community with the same name formed nearby.[11]

A “Monstrous Fish”

Two days after Christmas 1805, Clatsop Indians told the Corps of Discovery that a whale had washed ashore southwest of Fort Clatsop near a Tillamook village (modern day Ecola State Park.) Because of adverse weather conditions, Clark and other members of the Corps did not reach the whale until January 8. Sacagawea, who insisted on seeing “that monstrous fish” and the ocean, accompanied them.

By the time the party reached the beach, only the whale’s bones remained. The Nehalem Indians who had gathered much of the whale’s remains were reluctant to part with any of it, but Clark did manage to obtain approximately 300 pounds of blubber to add to the food supply and a few gallons of rendered oil. Lewis sampled the blubber and found it “not unlike the fat of Poark tho’ the texture was more spongey and somewhat coarser. I had a part of it cooked and found it very pallitable and tender, it resembled the beaver or the dog in flavour.”