Alberta officials gave U.S. legislators a tour of the province's oilsands as part of an economic summit this week.

Gary Mar, Alberta's envoy to Washington, led the tour Wednesday that included 12 American elected officials.

"We wanted to showcase the technology and innovation surrounding our oilsands development first-hand to this influential group," said Mar in a statement on Thursday. "I am confident that the legislators will go back to their home states with a much better understanding of our energy industry."

Alberta is increasingly coming under fire from American critics, including Hollywood director James Cameron, who say oilsands production leaves major environmental damage.

'I am more comfortable buying oil from Alberta, which shares similar environmental goals with the U.S., than from foreign sources.' —Mike Schaufler, Oregon state representative

Earlier this month, a U.S. group unveiled billboards comparing the oilsands to the BP oil spill and urging Americans not to travel to Alberta.

Two big U.S. retailers and a city in Washington state have all moved to avoid using fuel derived from Alberta's oilsands.

The provincial government's response has been to invite detractors to visit the oilsands for a first-hand look.

Delegates who were attending the Pacific Northwest Economic Region summer summit in Calgary spent all day in northern Alberta for the oilsands tour.

Mike Schaufler, a Democratic state representative from Oregon, said the tour gave him a fresh perspective.

"I was impressed by the technological advancements and the sophisticated pipeline transportation system used to transport oil to the U.S.," he said in a statement.

"I am more comfortable buying oil from Alberta, which shares similar environmental goals with the U.S., than from foreign sources."