A 450-ton shipment of oilfield equipment delayed by protests and bad weather in Eastern Oregon got permission from state officials for a daylight run on Tuesday.
It traveled 50 miles on a stretch at elevations above 4,000 feet where the state said ice was feared after dark.
The transport is headed for the Canadian tar sands oil development and has to pull off frequently to let traffic by. It had been restricted to night travel.
A spokeswoman for the moving company, Holly Zander, said the transport is due back on the road Wednesday night and could be in Vale on Thursday.
On Monday night, 16 people were arrested near John Day after environmentalists tried to block the rig. They say the tar sands development will contribute to global warming.