Tours of the fish viewing room at the McNary Dam will be offered each Saturday and Sunday morning of September.
The area is usually not open to the public, but offers some of the best underwater views into the fish ladder.
Visitors should check in by 10 a.m. with the security guard at the gate on the Washington side of the Columbia River, reached by taking Exit 131 from Highway 82. The walking tour will begin at the navigation lock visitor center.
Visitors age 18 and older will need to provide photo identification. Cameras, backpacks, cellphones, purses and other bags are not allowed.