Rajah Bose for The New York Times | Heavy drilling equipment staged at a port. Oil companies are negotiating to use Idaho and Montana roads, blocking other traffic. Imperial Oil’s shipments are headed for oil sands areas in Canada.
The proposed route could shave thousands of miles of transportation costs for such shipments, which might otherwise be forced to travel through the Panama Canal to overland routes accessed through Houston or New Orleans. Interstates and other wide highways are typically not an option, in part because overpasses are too low.
Transportation officials in Idaho and Montana say that their roads — with some modifications made and paid for by the companies, including additional pullouts along the route and raised or buried power lines — could handle the shipments. The plan calls for the loads to move only at night and in start-and-stop fashion, going down the road for a short time, then pulling over to let other traffic pass. For Imperial Oil’s trips, it would take the trucks nine nights to cover the 510-mile route through Idaho and Montana.
“We have done our level best to ensure, if given approval, that we can move these modules safely,” said Pius Rolheiser, an Imperial spokesman.
Eighteen-wheelers already traverse U.S. 12 here, which serves as a gateway to the Selway-Bitterroot Wilderness area, one of the largest tracts of virgin wildland in the contiguous United States. The road is also part of two national trails tracing routes followed by the Nez Perce tribe and Lewis and Clark.
But Mr. Laughy, whose home sits on a ridge above U.S. 12, about 75 miles east of Lewiston, says the oil equipment is different. He points to thin margins of error along U.S. 12, where the road slices a tight path between rising rock walls on one side and a quick drop-off to the river on the other. He also fears that sooner or later, an emergency vehicle rushing toward a fire or delivering someone to a hospital will be slowed by the meandering shipments, potentially costing lives.
“The companies say they have no plans to make this a permanent corridor,” he said. “But once the first shipment is allowed, what’s to stop the next one, and then the next one?”
Supporters of the shipments say they would inject millions of dollars into struggling rural economies along the route. “This wouldn’t be just an economic benefit for Lewiston,” said David Doeringsfeld, manager of the Port of Lewiston, “but for all of north-central Idaho.”
Mr. Doeringsfeld said he had been approached by several other companies interested in using the corridor.
In May, Mr. Laughy and Ms. Hendrickson started a Web site called Fighting Goliath, which serves as a clearinghouse of information related to the megaloads, as the shipments are called. The site has since drawn the attention of regional and national environmental activists, and a movement has mobilized around the goal of stopping the loads.
“I have never really seen so many people have such a unified voice against a project,” said Nick Stocks, a co-founder of Northern Rockies Rising Tide, a climate change advocacy group in Missoula, Mont., which is also on the proposed route.
Environmentalists abhor Canada’s oil sands — a gooey mixture of sand, clay and bitumen that can be refined into crude oil — as an energy-intensive and highly polluting energy source that generates large amounts of greenhouse gases.
But the oil sands are also one of the largest sources of foreign oil for the United States, and they are poised for further development. A proposed pipeline awaiting approval by American officials would add 1.1 million barrels of Canadian oil to the roughly two million already imported to the United States each day — much of it from the tar sands.
No permits have been issued yet in Montana. But when the Idaho Transportation Department granted a permit to ConocoPhillips in August, Mr. Laughy and Ms. Hendrickson, joined by a neighbor down the road and represented by the environmental law firm Advocates for the West, promptly sued the department, arguing that it had failed to adequately consider the safety and convenience of the public, as its own rules stipulate.
A lower court agreed. The case now rests with the Idaho State Supreme Court, which heard arguments on Oct. 1. and is expected to render a decision any day.
Meanwhile, both sides seem confident that they will prevail. Imperial has already floated the first of its 207 modules up the river to Lewiston, and it plans to move 40 of them there by early December.
Mr. Laughy, meanwhile, said that even if the court ruled against him, other obstacles — legal and physical — would probably emerge to stop the shipments.
“We’re really very nice people,” Mr. Laughy said. “Unless you’re a big oil company.”
Rajah Bose contributed reporting from Lewiston, Idaho.