The Siletz River basin covers an area of approximately 373 square miles. The river, which is just over 73 mi. long, drops 2900 ft. during its journey to the Pacific Ocean. The watershed is bordered by the Salmon, Neskowin, and Nestucca Watersheds to the north and the Yaquina to the south.
Starting as a trickle deep within the Coast Range in Polk County, the Siletz flows through two counties and the Siuslaw National Forest before emptying into the Pacific in a small tidal estuary. The Siletz River flows through two divisions of the Coast Range topography, the mountainous uplands and the flat coastal margin. The uplands are composed of moderate slopes (150-210 meters) near the terraces, but quickly become steep and rugged to the east. Typical elevations near the crest of the Coast Range reach 455-610 m, and higher peaks up to 1015 m about (e.g. Fanno Ridge, Stott Mountain, Laurel Mountain, Euchere Mountain). Ridges occur randomly, but tend to follow a slight northwest to southeast trend. Igneous rocks underlie the highest peaks in the range. The coastal margin consists of flat marine terraces at elevations of 15-60 m. These terraces average about 1.6 km in width and they are repeatedly broken by basaltic headlands extending seaward from the mountains. Tidal flow from the ocean extends 22.5 river miles inland, to just below Jack Morgan State Park.
Various tribes in the Siletz area built their houses of cedar boards, rectangular and semi-subterranean for greater warmth. Rush mats upon the earth floor served for beds. Fish formed their chief subsistence, supplemented by acorns, camas root, berries, wild game, and grass-hoppers; tobacco was the only plant cultivated. They had dug-out canoes, and were expert basket makers. Their chief weapon was the bow, and protective body armor of raw hide was sometimes worn. The dentalium shell was their most prized ornament and standard of value. Each linguistic group had its own myths and culture hero, or transformer, who prepared the world for human habitation. Among the Alsea these sacred myths could be told during only one month of the year. Among the principal ceremonies were the acorn festival and the girls puberty dance.
Before the beginning of the era of disturbance the Indians of the Siletz area may have numbered 15,000 individuals. In 1782-83 a great smallpox epidemic, which swept the whole Columbian region, reduced the population by more than one-third. A visitation of fever and measles about 1823-25 wiped out whole tribes, and by 1850 probably not 6,000 survived.
On their final subjugation the native people were removed by military force to the "Coast Reservation", which had been established under various treaties within the same period, and to which several tribes had already peaceably removed. In 1856, and for many years after, the federal government forced people out of their homes and livelihoods to come and live in a small part of the Oregon Coast known as the Siletz Reservation. The Coast Reservation originally extended some ninety miles along the coast, but by the throwing open of the central portion in 1865 was divided into two, the present Siletz agency in the north, and the Alsea subagency in the south. In 1876 the latter was abandoned, the Indians being concentrated on Siletz Reservation, to which about the same time were gathered also several vagrant remnant bands farther up the coast.
On 1 Sept., 1857, the Coast Tribe Indians were officially reported to number: Siletz Reservation, 2049; Alsea, 690; refugee hostiles in mountains, about 250; remnant bands north of Siletz, 251; total, about 3240.
Private industrial forest covers 75% of the Siletz Watershed. The largest community is Lincoln City, with a population of about 7,400. The community experienced a 21% increase in population during the period 1990-2000.
Salmon species found in the Alsea Watershed include coho, chum, fall chinook, and spring chinook salmon, winter and summer steelhead, and sea-run cutthroat trout.
During the 1990s the Oregon Department of Fish and Wildlife (ODFW) conducted surveys of returning native coho for coastal streams. ODFW random fish surveys for the years 1990 to 1999 for the Siletz Basin counted, on average, 857 spawning coho each year. In 1996, the watershed saw its lowest coho return for the decade counting only 336 wild fish. Historically, over 40,000 salmon spawned in the Siletz Watershed.
To learn more about the Siletz-Yaquina 4th field watershed, visit the U.S. Environmental Protection Agency's Surf Your Watershed website.
Coast Range Association. Salmon and Forests: A Report on the Siletz Watershed. Corvallis, Oregon. 2000. HTML document.
The Catholic Encyclopedia. Siletz Indians. Vol XIII.