Where in the Columbia River Basin have hydroelectric dams caused landlocked White Sturgeon populations?

In large areas of the basin where physical barriers, specifically hydroelectric dams, have effectively blocked upstream migratory movement.

Landlocked populations occur when physical obstructions, most notably dams constructed for hydroelectric power, sever the connection between the marine/estuarine environment and the necessary freshwater spawning grounds. In the vast Columbia River Basin, numerous hydroelectric dams have been erected, resulting in large segments of the river network that the sturgeon cannot ascend. Although some downstream passage via turbines has been observed, the upstream migration required for spawning is largely blocked in these regions, leading to populations restricted entirely to freshwater environments within that specific stretch of the river system. Landlocked populations are also recognized in Montana.