The massive containers filled with equipment at the Port of Pasco's barge terminal are on their way to Canadian oil fields.
The modules that arrived at the port this summer just recently started moving on state highways.
And more containers were unloaded Sunday and Monday from barges shipped from Vancouver, Wash., said Sam Good, the port's director of properties and development.
Jon Harding, a spokesman for Imperial Oil, said the Washington State Department of Transportation gave the company authorization Sept. 16 to move the loads on Highway 395 and Interstate 90.
Since then, about 10 shipments have used the route, which also includes Interstate 15 to reach Canada.
The equipment is headed to the Kearl Oil Sands Project -- an Alberta open-pit mining operation. Oil sands are a mix of heavy oil known as bitumen, water and sand that is about the consistency of peanut butter.
The Kearl project will be one of Canada's largest open-pit mining operations with eventual plans to produce up to 345,000 barrels a day beginning as soon as late next year.
The shipments were re-routed through Washington after environmental groups slowed the permitting process for using Idaho's scenic Highway 12 for the loads.
Earlier this month a Montana judge modified a preliminary injunction to allow officials to review and permit the loads to travel on the two-lane route, according to The Associated Press.
Harding said Imperial Oil plans to continue using the Washington route, as well as pursuing its preferred Highway 12 route.
"We plan to use all routes available," he said.
Since July, ExxonMobil and its Canadian affiliate, Imperial Oil, have used another alternate route from the Port of Lewiston in Idaho that uses Highway 95, I-90 in Idaho and Montana, and I-15 to Canada.
So Harding said it's difficult to determine how many containers will end up going through the Port of Pasco.
So far, the loads traveling on Highway 395 are 208-feet long or less, about 20- to 24-feet wide and 10- to 15-feet high. They weigh 212,000 to 345,000 pounds.
Mammoet Canada Western Ltd., the company moving the loads from the barges to the trucks, has leased 22 acres including land at the port's container yard to store the containers.
The lease is month-to-month, and costs about $7,300 a month. The port also collects fees for terminal use. The amount of money collected by the port so far was not immediately available Tuesday.
Good said the port has demonstrated that it can accommodate moving of heavy loads. And she said she hopes to see more companies using the river for shipping materials.