DES MOINES, Iowa (AP) — Work has begun in Iowa on an oil pipeline despite repeated attempts by landowners and environmental groups to stop it.

The Iowa Utilities Board signed a final order Wednesday allowing construction on the $3.8 billion, 1,150-mile pipeline. And Lisa Dillinger, a spokeswoman for Texas-based Dakota Access, which is building the pipeline, confirmed Thursday that work is underway.

The pipeline will carry oil from North Dakota across South Dakota and Iowa before ending at a storage facility in Illinois.

Iowa was the last state to approve construction. Work began last month in the other three states.

The project faces at least five lawsuits and opposition group Bold Iowa said Thursday that 60 members have signed a pledge to risk arrest if necessary in nonviolent protests.