Tillamook Bay is on the Oregon coast, 50 miles south of the Columbia River.
The Corps owns and maintains two jetties at Tillamook Bay's entrance. The north jetty, originally built in 1914, was reconstructed and extended to its authorized length of 5,700 feet in 1931. A revetment was constructed in 2004 to help prevent shoreline erosion and protect the vulnerable north jetty root. In 1965, construction of an 8,000-foot-long south jetty was authorized. Work began in 1969; the first segment was finished in 1971. Construction of the second segment was completed in 1974. Construction of the third segment— 1,500 feet to complete the 8,000-foot jetty— started in 1978 and was completed in 1979.
In spite of extensive rehabilitation over the years, the increasingly tumultuous Pacific Ocean environment has caused recession of both the north and south jetties. The revetment has also experienced some damage caused by wave overtopping which over time destabilizes the stones and causes erosion within the structure. A 2010 rehabilitation project capped the north jetty at its current length of 5,213 feet and made necessary repairs to the revetment. Corps contractors placed more than 1,000 stones weighing 25 to 50 tons each on existing relic stone base, creating a new jetty cap. Jetty head repairs created a broader, higher and more substantial structure to withstand the attack of powerful waves. The 100-foot cap on the north jetty is designed to stop further recession of the jetty, stabilize the jetty head, and reduce forces on the trunk and root of the jetty.
The Corps of Engineers does not maintain recreation facilities at this location. Stay off the jetties as they are hazardous and not intended for recreational use. Nearby adjacent recreational facilities fall under the jurisdiction of private, local or state agencies. Learn more about jetties and why they are unsuitable for recreation at Understanding Coastal Jetties.