Mitch -
The Sky Chinook are what is commonly called a summer Chinook. While some fish begin showing up in late April and May most of the fish enter the river in late June and early July.

On WDFW's hatchery escapement report -
http://wdfw.wa.gov/hat/escape/escape.htm

a total of 4,165 fish returned to the Wallace hatchery in 2006. 60 were collected by 6/7 and 2,303 by 7/6.

Tight lines
Curt