Indigenous people in the U.S. and Canada say they’re being excluded from negotiations for a new Columbia River Treaty, which kick off next week.

The Confederated Colville Tribes and 14 other tribes along the river spent months trying to secure a seat for tribal representation at the negotiating table, said Michael Marchand, the Colville chairman.

However, the State Department’s announcement this week about formal talks starting Tuesday doesn’t include the tribes. It listed the Bonneville Power Administration, the U.S. Army Corps of Engineers, Department of Interior and the National Oceanic and Atmospheric Administration as participants.

“It is unfortunate that tribal nations, who know the Columbia better than anyone, are excluded from the treaty re-negotiation process,” Marchand said in a news release. “These are the people with the longest and deepest connections to the Columbia River, the people who have respected and depended upon the river and its salmon and other natural and cultural resources for thousands of years.”

The State Department issued a statement saying its staff would consult with the tribes on a regular basis as treaty negotiations proceed.

In Canada, First Nations have expressed similar concerns about not being involved in their country’s negotiations.

The 1964 treaty was designed to increase hydropower and hold back floodwaters along the 1,200-mile river, which starts in British Columbia and flows to the ocean. Dams built as a result of the treaty flooded sacred sites and burial grounds and affected fish runs, First Nations said.

Not including First Nations in the negotiations threatens Prime Minister Justin Trudeau’s stated commitment of meaningful reconciliation with Canada’s indigenous peoples, said Grand Chief Stewart Phillip, chairman of the Okanagan Nation Alliance.

The treaty doesn’t have an expiration date, but either country can cancel most of its provisions after September 2024, with a 10-year minimum notice.