JUNEAU (AP) — The trans-Alaska pipeline has moved its 17 billionth barrel of oil.

The operator of the 37-year-old pipeline, Alyeska Pipeline Service Co., announced the milestone Monday.

It has been nearly five years since the 16 billionth barrel flowed down the line, in October 2009.

The 800-mile pipeline is the economic lifeblood of the state, which relies heavily on oil revenues to run. The pipeline runs from the prodigious North Slope to Valdez, from where tankers are shipped.

Alyeska says the pipeline has generated about $180 billion in state revenue.

Oil flowing through the line has been on a downward trend since reaching a peak of 2.1 million barrels a day in the late 1980s.