34 U. S. BUREAU OF FISHERIES 
runs of fish. The method decided upon provided for the trapping 
of all upstream migrant salmon and steelhead trout at Rock Island 
Dam near Wenatchee, Wash., and the construction of holding ponds 
and a large hatchery on the Icicle River, a tributary of the Wenatchee 
River, near Leavenworth, where the adult fish would be held until 
the sex products were ripe and the fish were stripped. Subhatcheries, 
or rearing stations, located on the Methow, Entiat, and Okanogan 
Rivers are also part of this plan. These stations are to be used for 
the hatching of the eggs taken from the adults at Leavenworth, after 
which the young fish all be reared and liberated in the river system 
where the subhatcheries are to be located. All of these streams enter 
the Columbia River below Grand Coulee Dam and above Rock Island 
Dam. Because of the fact that chinook and blueback salmon have 
an extremely strong and uniform habit or tendency to return to the 
stream in which they were reared and lberated, it is believed that 
the fish resulting from the hatchery operations will return to these 
streams below Grand Coulee Dam, thus making trapping operations 
unnecessary at some future date. 
By the spring of 1939 the construction of Grand Coulee Dam had 
proceeded to such a point that fish could no longer pass beyond the 
dam site. Unfortunately, construction of the h: itcheries was unavoid- 
ably delayed. Therefore, emergency measures had to be taken to 
accomplish the salvaging of the runs, 
It was decided to ‘trap the fish in the fish ladders at Rock Island 
Dam and to transport them to 3 of the streams entering the Columbia 
between that place and Grand Coulee Dam, where they were liberated 
and allowed to spawn naturally. In this way the transfer to the 
streams below Grand Coulee Dam was begun, but with natural 
spawning taking the place of the hatcheries. 
The permanent trapping equipment at Rock Island Dam was com- 
pleted last spring and was used to catch the fish in the salvage pro- 
gram. Also, 8 specially built tank trucks, which will be used to 
transport fish from Rock Island Dam to the Leavenworth hatchery, 
were used to haul the salmon and steelhead trout to the desired loca- 
tions. These trucks each have a capacity of 1,000 gallons and are 
equipped with auxiliary motors, pumps, and compressors which 
aerate and circulate the water in the tanks. The water is cooled by 
circulation through ice compartments. 
Because of information previously collected by the stream-survey 
crews, it was possible to select areas in the Wenatchee, Entiat, and 
Okanogan River systems which were suitable for the spawning ac- 
tivities of the salmon and steelhead trout. Chinook salmon and 
steelhead trout were placed in Nason Creek, an upper tributary of 
the Wenatchee River, the main Wenatchee just below Wenatchee Lake, 
and in the “stillwater section” of the Entiat River. The young of 
the blueback salmon require a lake for their fresh-water habitat; 
so that species was planted in Wenatchee and Osoyoos Lakes. Fish 
weirs, or racks, were constructed at the lower end of each stream sec- 
tion or lake in which the spawners were placed, so that the fish would 
not stray downstream and perhaps back into the main Columbia 
where they might be unable to find or reach suitable spawning areas. 
The actual hauling of fish began on May 1, and the last load was 
transported on December 9. All of the salmon in the 1939 run were 
