Boeing Creek flows out under the tracks a mile or south of Richmond Beach, in a ravine that runs between the posh chateaus of the Highlands and the upscale, but somewhat less posh, suburban tracts of Innis Arden.
The creek flows through a concrete box culvert (as does the walkway) dated 1951, but there are old rusty culverts dating, I assume, to it's previous path.
It's an interesting contrast to the Elwha from the week before. It's obviously a much smaller stream to start with and I also suspect that the delta is composed not only of stream sediment but also a significant fraction of sediment eroded from bluffs farther south, transported north by waves, and trapped in the complex dynamics of the creek delta. Like the Elwha (particularly recently), there are broad sandy bars extending far offshore on the downdrift side of the stream mouth.
Like many streams in this part of the sound, Boeing Creek reaches beach level upstream of the mouth of the valley, suggesting that it may have originally been graded to a lower sea level and then its valley floor rose in pace with rising sea level over the past few thousand years. The railroad has altered both the landscape and the movement of sediment, obscuring the historic pattern of alluvial valley, wetlands, estuary, and stream mouth spit - all of which were likely present to some small extent.