ARLINGTON — More than 150 years after signing a treaty ceding land but preserving their hunting and fishing rights, Columbia River tribes are locked in a legal dispute with this tiny port over whether those rights can change with the course of the river.

The Port of Arlington wants to build a barge pier near the confluence of the Columbia and Willow Creek. Arlington officials say the pier, intended to handle garbage barges, is critical for Gilliam County’s brittle economy.

But area tribes argue the pier would interfere with their fishing at the site, violating terms of an 1855 treaty that guarantees their right to hunt and fish in “usual and accustomed” areas.

The U.S. Army Corps of Engineers initially approved a permit needed to build the pier, but last year revoked it after looking into the tribes’ complaints and deciding they might be right.

The disagreement hinges on whether the permit should have been pulled and what constitutes a “usual and accustomed” tribal fishing site.

The Confederated Tribes of the Umatilla Indian Reservation — backed by three other tribes in the region — contend the pier site is in the middle of a fishing ground protected by the treaty. Officials in Arlington and Gilliam County dispute that, saying a dam built on the Columbia four decades ago submerged the actual fishing grounds.

Work had already begun on building the pier when the Corps ordered construction stopped.

The Port of Arlington has taken the matter to federal court in Portland, where it will be heard on Aug. 5.

“We feel ganged up on by the Corps of Engineers and the four tribes,” said Port commissioner Tim Wetherell, who argues that a decision in favor of the tribes could put a chill on development in other communities along the Columbia.

A string of hydroelectric dams were built along the Columbia starting in the 1930s, inundating tribal fishing grounds.

Local officials say the pier is needed to ensure that a nearby landfill is able to compete with other landfills.

Currently, garbage from the Portland area is trucked to the landfill. The landfill operators pay a $3 million annual “host fee,” far from chump change to a county the size of Rhode Island with only about 2,000 residents. The landfill provides about 150 jobs and is the county’s largest employer.

The port fears a new 10-year contract to truck garbage along Interstate 84 through the protected Columbia River Gorge National Scenic Area may not be renewed for environmental or other reasons, hobbling the landfill.

Laura Pryor, a Gilliam County judge for nearly 20 years, calls the landfill “the salvation of the county,” adding that the county competes with landfills that have delivery by rail, highway and barge.

“If we can’t compete on an even field, we don’t have a chance,” she said.

Umatilla tribal attorney Brent Hall said a fishing village existed near the site where Arlington wants to build the pier, making it a “usual and accustomed” site protected by the treaty.

The port argues that at the time of the 1855 treaty the shoreline was about 300 feet from the location of the unfinished pier, so the construction site could not have been a fishing site when the treaty was signed. The Columbia rose about 40 feet with construction of the John Day Dam, flooding miles of riverbank.

The tribes, backed by the Corps, counter that protected fishing sites can move with rising river levels and fish patterns.

“The fact that the present location of tribal fishing has shifted with the shoreline and is not precisely where fishing took place in 1855 does not negate its qualifications as a usual and accustomed fishing station,” the Corps wrote in papers filed in federal court.

The 1855 treaty with the U.S. government was signed by the Cayuse, Umatilla, and Walla Walla tribes, who ceded more than 6.4 million acres in what is now northeastern Oregon and southeastern Washington. In return they got land that was designated as the Umatilla Indian Reservation, which consists of 172,000 acres. The treaty was signed by a number of other tribes as well.

Also under the treaty, the tribes reserved perpetual rights to fish, hunt and gather traditional foods in the ceded lands.

As compensation for the submerging of fishing grounds by dams on the Columbia, the federal government has provided tribes with “in lieu” fishing sites, most of which were Indian-only access routes to their fishing grounds.

Blood boiled for decades over attempts by white settlers to keep tribal fishermen from crossing their land to get to their fishing sites.

Kathryn Brigham, past chairman of the Columbia River Inter-Tribal Fish Commission, said the tribes have fought in court before over their rights. She has been active in Columbia River tribal fishing issues for more than half of her 62 years and recalls hostility at hearings on tribal fishing seasons in the mid-1970s.

“People were yelling at us. They carried signs that said, ‘Save a salmon, can an Indian,’ “ she recalled.

Paul Conable, attorney for the Port of Arlington, said the port supports more in-lieu sites for the tribes.

That tribal fishermen who lost fishing grounds were not better-compensated is shameful, he said, “but it’s not the port’s fault.”