A coalition of environmental groups is publishing this anti-oilsands ad in a Wyoming newspaper as western U.S. governors hold their annual meeting in the state. (Natural Resources Defence Council)

A coalition of environmental groups has launched another attack on the Alberta oilsands, this time targeting the meeting of U.S. western governors which begins Sunday in Jackson Hole, Wyo.

The groups have taken out an ad, to be published Monday in the Casper (Wyoming) Star Tribune, which features photos of a giant open pit tar sands mine, and another of an oilsands plant belching smoke. At the centre of the ad is a postcard inviting the governors to hold their next meeting in Fort McMurray, the centre of oilsands production in northern Alberta.

"We can watch as pristine boreal forests and wetlands are destroyed to produce some of the dirtiest oil," the message printed on the postcard reads in part.

The environmentalists have also sent a letter to the 22 governors explaining the damage they feel the oilsands production causes.

"There are many environmental groups on both sides of the border that are very concerned about the impacts of tar sands on the environment and public health," said Susan Casey-Lefkowitz, with the Natural Resources Defense Council in Washington, D.C., one of the groups that paid for the ad.

"Alberta is talking about doing the right thing. But they haven't yet started really taking action to do the level of cleanup that's needed to protect the boreal forest, to protect the health of the communities in the region and to deal with the toxics issues, and certainly not to deal with the global warming issues."

So much misinformation: Alberta premier

Alberta Premier Ed Stelmach, who is attending the three-day meeting, was hoping to use the session to counter recent attacks on the oilsands by those who say it comes at too high an environmental cost.

"There's so much misinformation," said Stelmach when told about the ads Friday.

"I'm going there specifically to share the correct information, the facts about Alberta's energy production, our legislation what we've accomplished so far."

Stelmach insists the province's own climate change plan, which focuses on capturing the carbon dioxide emissions and storing them underground, will offset any increased impact caused by oilsands production.

Latest blow to the reputation of Alberta oilsands

Earlier this week, an association of U.S. mayors passed a resolution urging American cities to stop using fuel from the oilsands, saying it produces three times the carbon emissions it takes to produce conventional oil.

In the past few days Greenpeace launched its own attack, with a mock tourism website inviting people to vacation in the Fort McMurray area so they can enjoy fishing in oilsands tailings ponds or basking in the scenery of an open-pit mine.