J.E. McAmis Finishing Long-Term Jetty Project Along Columbia River

J.E. McAmis is wrapping up a 10-year project on the South Jetty along the Columbia River in Oregon. The $172 million endeavor involved placing 450,000 tons of stone to maintain the river's navigation channel. The project supported local economies and ensured safe passage for vessels into the Pacific Ocean.

August 19, 2025 - West Edition #17
Lori Tobias – CEG Correspondent

U.S. Army Corps of Engineers photo

This Cat 6020B excavator is outfitted with a customized front end, boom, stick, bucket and thumb specifically for jetty work.

A crane lifts a jetty armor stone into place while a Komatsu PC1250-11 excavator works in the foreground. (U.S. Army Corps of Engineers photo)

A Komatsu PC1250-11 excavator prepares to grab a jetty armor stone right in front of a crew member. (U.S. Army Corps of Engineers photo)

Only two excavators worldwide are fitted with this configuration. (U.S. Army Corps of Engineers photo)

Repairs are nearly complete on the South Jetty on the Columbia River. (U.S. Army Corps of Engineers photo)

Work on the largest rubble mound jetty in the world is coming to a close, ending 10 years of continuous jetty work in Clatsop County, Ore.

The South Jetty on the Columbia River, one of three jetties making up the river jetty system, is the last of the three to undergo critical repair work. The $172 million project got under way in 2019, following work on Jetty A and the North Jetty.

"Where are we with that now is we're nearing completion of a six-year project," said Colter Bennett, U.S. Army Corps of Engineers project engineer. "We're in the final stretches of the final season. In terms of stone placement, I think we're a month away, but the site still needs major site restoration."

The South Jetty was originally built starting in 1885 and has undergone repairs 10 times since then, Bennett said.

U.S. Army Corps of Engineers photo

"This effort is the largest stone quantity that's been put on the jetty in a single project since the original construction."

By the project's end, the contractor, J.E. McAmis, of Chico, Calif., will install 450,000 tons of jetty armor stone.

"One way to think of it is that is about 34,000 Volkswagen Beetles," Bennett said.

"As a result of the jetty's size, the contractor had to go many different places to find the quantity of rock. The production rate of jetty armor stone is slow, so you have to go to multiple quarries that are producing armor stone at the same time — and producing fast enough — to finish the job on time. They had seven main contributing sources of stone, and all of these sources are in both Oregon and Washington."

Most of the work on the jetty was completed with a Cat 6020 excavator outfitted with a customized front end, boom, stick, bucket and thumb specifically for jetty work, Bennett said.

"There are only two in the world outfitted that way, and one is in Coos Bay, and one is at the South Jetty."

Combined, the three jetties total 9.7 mi. in length and are regularly pounded by waves 10 to 20 ft. high and more than 30 ft. during winter storms. Their purpose is to provide navigation through the channel of the Columbia River into the Pacific Ocean.

"There's so much sediment that's coming out of our rivers into the ocean and, at that interface, at tends to fall out of suspension and that makes for shallow water," Bennett said. "If you add jetties, they constrict the width valve where the river is discharging into the Pacific Ocean. That speeds the velocity of that water up and keeps the sediment in suspension ... instead of dumping the sediment right at the mouth where ships are trying to come and go. That's their main purpose ... to keep that channel deep and in the same exact spot."

The South Jetty project was originally budgeted at $166 million but increased in cost by about $6 million.

"We had to add more rock to the contract," Bennett said. "Also, we had to install a revetment to protect the haul route the trucks drive on to deliver the stone. That needed to be armored because the ocean was taking it away essentially."

U.S. Army Corps of Engineers photo

The number of jobs created by the project isn't readily known.

However, Bennett noted that the project is not just a transaction between the government and contractor, but that the contractor relies on a "whole suite of subcontractors — mechanics, welders, stone suppliers, truckers, small parts, safety equipment. They have partnerships in many different industries. So, Astoria feels it in a big way. One of the main stone suppliers for both armor stone and also road material is Big River excavation out of the Astoria area. They rely on that contractor to produce a lot of the material for them and provide the trucking of equipment.

"So, the economics of these projects are huge. That money goes everywhere. The last figure I've heard and seen published is $31 billion worth of cargo annually moves through the mouth of the Columbia River. That provides a lot of the justification to spend this amount of money and make sure that the cities are in great shape all the time."

The South Jetty project follows a one-year, $20 million repair project on Jetty A, completed in 2017 and a $39 million project on the North Jetty completed in 2020. CEG

Lori Tobias

Lori Tobias is a career journalist, formerly on staff as the Oregon Coast reporter at The Oregonian and as a columnist and features writer at the Rocky Mountain News. She is the author of the memoir, Storm Beat - A Journalist Reports from the Oregon Coast, and the novel Wander, winner of the Nancy Pearl Literary Award in 2017. She has freelanced for numerous publications, including The New York Times, The Denver Post, Alaska Airlines in-flight, Natural Home, Spotlight Germany, Vegetarian Times and the Miami Herald. She is an avid reader, enjoys kayaking, traveling and exploring the Oregon Coast where she lives with her husband Chan and rescue pups, Gus and Lily.