WOW... There's NOTHING like your NW insitus...They are gorgeous colored materials, They are ALWAYS wet ( either by rain or river waves )...nice gravel on a bed of Mt Saint Helens Ash.
Re that pretty boat pic....Have you noticed this phenomena......
On the Gulf coast, the port entrance at Port Aransas is between Jetties that are probably a thousand feet apart. While fishing well inland from the entrance to the jetties, I was shocked and amazed that when a deep laden vessel ( tanker or cargo ) approached, the water level receded by as much as one foot. Then well after the vessel went by, it returned to "normal"
It happens so fast, small fish & shrimp are flipping around on dry land !
Have you noticed anything like this on the river? If not it might be too wide.