The photos were taken at the mouth of the Samish River, Skagit County, Washington. The nearest town would be Mt. Vernon, about 15 miles away and a population of around 27000. I would venture to say a good number of those people fishing are not from Skagit County. Seen several cars parked on the road with Canadian license plates. Likely many from The Seattle area also.

The pilings are as UJ said; to prevent the dike from erosion during high water events.

The photo of where I was fishing was taken at the forks of the Skagit River.