This is part of the amazing Pack River Delta. In the middle of the photo that is at the end of the delta with the lake just beyond is the Pack River Trestle. The original Northern Pacific Railway’s 6,500-foot, curved, wooden trestle built in 1882 that extended from Hawkins Point on the Sunnyside Peninsula to this site across Pack River Bay just west of the creek. At low water, the old pilings of the trestle are still visible. The existing train crossing was built in 1904.

I think you are looking at the Coeur d'alene Mountains to the west.

The square platforms on short posts seen here and there in the estuary are man-made nesting boxes that were installed some years ago for Canada geese. The more recent restoration work included creating islands that trap sediments, eventually producing marshes and enhancing nesting habitat for many species. Ducks Unlimited was the coordinating organization for this restoration project.