BOISE, Idaho (AP) — The Nez Perce tribe in north-central Idaho said Friday it doesn't want 200 over-sized loads of oil-field equipment traveling a reservation highway en route to an oil sands project in Canada.

The tribal government passed a resolution concluding the giant shipments, scheduled to move at night starting this fall along U.S. Highway 12, "would establish a dangerous and unacceptable precedent in one of the most beautiful and pristine federally protected corridors in the U.S."

The Nez Perce also wrote that extracting petroleum from the Kearl Oil Sands in Alberta was an "environmentally destructive method ... that will have profound negative impacts on the First Nations communities of Canada."

The shipment route, starting from the Snake River port of Lewiston, follows the Lochsa and Clearwater rivers through 70 miles of the Nez Perce reservation in Idaho. With its resolution, the tribe joins others who fear potential environmental and safety risks from loads that could weigh up to 140 tons and be 170- to 210-feet long.

"The tribe will explore all options in terms of achieving our policy goals," tribal attorney Mike Lopez told The Associated Press Friday, adding the Nez Perce haven't considered a blockade to thwart the shipments.

"The tribe is aware that the state has a right of way though the Nez Perce reservation," Lopez said. "The tribe hasn't considered pursuing that possible avenue yet."

The Idaho Transportation Department has said state law requires the agency to issue permits for the huge loads, provided they can be moved safely and without damaging roads and bridges.

The agency joined Canada's Imperial Oil, the unit of Exxon Mobil Corp. that's behind the shipments, in giving presentations in Moscow and Lewiston this week, detailing just how the company will transport the equipment.

But the tribe said it isn't satisfied with assurances, saying Highway 12, completed in the 1960s, was never envisioned as a transportation route for gigantic equipment that could go crashing into the Clearwater or Lochsa rivers if there's an accident.

"The tribe fails to see how the nominal benefit of this project to the local area will justify the enormous risks to people and the environment," said McCoy Oatman, chairman of the Nez Perce Tribal Executive Committee, in a statement.

A spokeswoman for Imperial, which contends on its website that the oil sands project is "environmentally, socially and economically responsible," didn't immediately return phone calls seeking comment.

Imperial has said the equipment transports would bring $10.6 million to Idaho, with most going to wages for drivers of pilot cars. Montana is expected to receive about $1,600 a load from the company to cover costs, while the Idaho Transportation Department estimates it will get about $1,000 per load.

The Idaho Transportation Department issues fewer than 10 oversized permits per year for Highway 12, usually for grain silos, boats or wind turbine blades. There have been no reported accidents involving oversized loads here in 15 years.