Since the 1700s, when
the human impact on salmon was limited to native fisheries, salmon have
been increasingly affected by the Northwest's growing population and
economy.
The first major European impact on the natives of the Columbia River
occurred in the 1770s, when the first diseases struck native peoples. By
the mid-1800s, European diseases reduced
their population by 90% and the Columbia's
resources were being exploited for the benefit of the new settlers.
By the 1890s, dams were affecting salmon runs; hydroelectric and flood-control projects
eventually reduced the area available to salmon by half. Salmon in the
Columbia are also affected by grazing, irrigation, logging, mining,
overfishing, pollution, urbanization, ocean conditions, and predators.
As the Northwest's population and economy grow, the future of wild salmon is uncertain. Plans for improving the
status of salmon have become increasingly common, but many projects simply
undo the damage caused by past generations of well-intentioned developers.
An historical perspective is essential for understanding the current and
future status of salmon and steelhead in the Columbia Basin. How has
the Columbia changed from 1770 to the present?
These maps and graphs
illustrate how humans have altered the river and how these alterations
have affected salmon survival. Introduction
The Columbia Basin in 1770
The Columbia Basin in 1940
The Columbia Basin Now
Other Salmon Links
![]() |
![]() |
![]() |
![]() |
![]() |
To Index | To Columbia River History | To Regional Data | To Related Sites | To References |