Eagle crk. goes under I 84 and the railroad bridge at Eagle crk. Hatchery so that is the mainline railroad bridge in the regs.
agreed, main railroad line is the one running right along the side of the Columbia river....
regs. page 88
Description:
The Columbia River Zone is all waters of the Columbia River upstream from a north-south line through Buoy 10 at the river mouth
and
includes those portions of tributaries (including lakes) downstream from the mainline railroad bridges near the tributaries’ mouths
except for the Willamette (including Multnomah Channel), Sandy, Hood, Deschutes and Umatilla river systems and Youngs Bay.
The Columbia River Zone includes downstream from Hwy 730 on the Umatilla River and from Interstate 84 on the Deschutes River.
The boundary is a straight line across the mouths of the Willamette (including Multnomah Channel), Sandy and Hood rivers and the
Hwy 101 Bridge on Youngs Bay