In 1840, Solomon H. Smith, a resourceful frontiersman, became the first white settler on the Clatsop Plains. Married to Celiast, a Clatsop woman, Smith built a log house about five miles south of the Columbia on the north Clatsop Plains. With the Rev. J. H. Frost, who had arrived that year on the missionary ship Lausanne, Smith constructed a mission house a mile north of his home. His skills included boat-building, school teaching and law; he opened a store in Lexington (later Skipanon) on the Skipanon River, and also ran the first ferry across the Columbia. The Eldridge Trask and W. T. Perry families were among the early arrivals, settling near the Smith Claim. Thomas and Sarah Owens arrived in December 1943; Smith took them by wagon via the beach to their farm claim.

The Owenses brought the first flax into Oregon from Kentucky. The Eberman family, with 16 children, owned land from the north Plains to the Necanicum. The William Hobson, George Summers, J. L. Parrish and Calvin Tibbetta families all homesteaded in the early 1840s. Philip Gearhart moved to his homestead in 1849, two miles north of Seaside, bringing his wife and 4 children by Chinook canoe. His site became the future Gearhart, Oregon. Gearhart started a dairy business on his farm.

Livestock and dairying were important to the early economy. The British Northwest Co. had introduced the first livestock in the region during the War of 1812. Solomon Smith was reportedly the first dairyman in the territory. He and J. H. Frost had driven the first herd of cattle across the Coast Range, then up the coast to Smith's farm. In 1842, Calvin Tibbetts and others helped establish further cattle routes through the mountains. These were essentially old Indian wilderness trails. Clatsop settlers, guided by Indians, went by canoe to Fort Vancouver in 1842 to purchase horses and cattle which they drove overland to the Plains.