Chinook Salmon

Considering the fate of salmon, you'd probably guess the Hanford Reach is a nationally important fishery. You might not guess that it's also internationally important, so much so that in 1998 the Governor of Alaska sent a representative all the way to the small community of Mattawa to testify before a Senate hearing on its importance.

The Monument includes the Hanford Reach, the nation's last, non-tidal, free-flowing segment of the Columbia River. Forty-three species of fish have been documented as occurring in the Hanford Reach. Salmonids are of particular interest; large numbers of fall chinook salmon spawn in the Hanford Reach. Other plentiful species in the river are redside shiners, carp, largescale suckers, northern pikeminnow and peamouth. Mountain whitefish are common in the Hanford Reach and support a recreational fishery. Sunfish and perches can be found, although they are more common in McNary Reservoir, but smallmouth bass are abundant in the Hanford Reach.

The ponds and lakes created by irrigation run-off also have populations of introduced fishes, such as carp, bass, sunfish and panfish.

Riparian vegetation and backwater sloughs are very important for fisheries habitat. Shoreline vegetation provides shade, moderates temperatures in shallow water and provides shelter and substrate for invertebrate populations,all of which are critical for sustaining fish populations.

Salmon are the fish of greatest concern. Read on for more information.

Chinook Salmon Smolts



As noted earlier, large numbers of fall chinook salmon spawn in the Hanford Reach. Upper Columbia River spring chinook, listed as a federally threatened species, also use the Hanford Reach for migration, as well as both the Middle and Upper Columbia River steelhead, both of which are federally threatened species.

The Hanford Reach is the last free-flowing section of the Columbia River upstream from Bonneville Dam. The Hanford Reach contains islands, riffles, gravel bars, oxbow ponds, and backwater sloughs that support some of the most productive spawning areas in the Northwest, including the largest remaining stock of wild fall chinook salmon in the Columbia Basin. The loss of other spawning grounds on the Columbia and its tributaries has increased the importance of the Hanford Reach's fisheries. Juvenile production is approximately 20-30 million individuals annually.

In July, 2000, the FWS was assigned responsibility for overseeing the interim protection of the "outstandingly remarkable" values that made the Hanford Reach of the Columbia River suitable for addition to the National Wild and Scenic Rivers System, including fall chinook salmon. Fall chinook salmon that spawn and rear throughout the Hanford Reach are of economic and cultural importance to commercial fisheries in the North Pacific Ocean, in-river commercial and tribal fisheries, and ocean and in-river sport fisheries. This stock is also a principal component of the international Pacific Salmon Treaty between the United States and Canada.

Adult spawning in the Hanford Reach has ranged from approximately 20,000 to 90,000 over the last 35 years. Streamflows in the Hanford Reach are intentionally limited during the fall chinook spawning season (October-November), with the stated goal of confining spawning activity to lower river elevations that can be maintained through the winter/spring incubation and emergence time period (through mid-June). Streamflows vary between lower, late-winter levels and higher spring freshet flows during the spring juvenile fall chinook rearing period from mid-March through mid-June.