The Lummi Nation and the Yakama Nation are calling for the removal of three major hydroelectric dams on the Columbia River.

Editor's note: Video explains how breaching dams to save Northwest orcas is a contentious issue

Two Pacific Northwest tribes are calling for the removal of three major hydroelectric dams on the Columbia River.

The Lummi Nation and the Yakama Nation said Monday that the U.S. government violated a treaty from 1855 when it built the concrete dams on the lower Columbia River.

The construction of the Bonneville, John Day and Dalles dams destroyed important native fishing sites and deeply impacted the migration of salmon.

The Yakama traditionally fished for salmon along the river and the Treaty of 1855 guaranteed the tribe access to those sites even after the tribes ceded 11.5 million acres to the U.S.

Salmon are also the preferred prey of endangered orcas, which were traditionally hunted by the Lummi Nation.