The treaty, signed in 1964, governs operations of dams and reservoirs that have caused salmon run declines.
Tribes are pushing to include salmon restoration to the upper Columbia, above Grand Coulee Dam in northern Washington State, in the treaty.
In recommendations for potential negotiations, the U.S. says the two countries should study the possibility of restoring fish passage over that dam. But Canada says restoring fish migration and habitat is not a treaty issue.
Seventeen vigils will be held along the length of the river, in Oregon, Washington state and British Columbia.