How did dams on the Columbia River affect treaty-protected Plateau fishing rights?

The construction of dams along the Columbia River has significantly impacted the traditional fishing practices of Indigenous peoples in the region. These developments, which began in the 1930s, resulted in the loss of traditional fishing sites and created severe obstacles for migratory fish populations, particularly salmon.12

The dams have negatively affected these treaty-protected rights by:

• Blocking Migration: Dams serve as physical barriers to upstream migration, and power-generating equipment poses risks to fish survival.23
• Habitat Loss: The creation of reservoirs led to the inundation and destruction of vital spawning grounds.2
• Environmental Degradation: Changes to the river's flow, including the loss of natural currents that guide spawning fish and the supersaturation of water with nitrogen at spillways, have further hindered fish populations.2
• Population Decline: Despite the installation of fish-passage facilities, such as ladders and locks, these measures have struggled to sustain fish numbers, leading to dramatic declines in salmon runs compared to historical levels.23

While these dams were instrumental in regional economic development, their impact on the river's ecology has fundamentally challenged the ability of Plateau Indian tribes to exercise their traditional fishing rights.12