This topic has been covered in the past on this board and others. I remember posts by knowledgable people,dan s, todd,cowlitzfisherman and others.

Here's my information.

The U.S. Supreme Court has ruled that rivers that are navigable ,for title purposes, are owned by the states,"held in trust" for the public. This applies in all fifty states.

The federal test of navigability is not a technical test but simply whether the river is usable as a route by the public.

The states own these rivers up to the "ordinary high water mark." This is the mark that people can actually see on the ground where the high water has left debris, sand,and gravel during its ordinary annual cycle.

State governments cannot reduce public rights to navigate and visit navigable rivers within their borders,but they can expand those rights. They can create a floatage easement, a public right to navigate even on rivers that are non-navigable, when the water is there, people have a right to be there on it , when it dries up people have no right to be there. But rivers that are navigable for title purposes are public land up to the high water mark,so even when the river runs dry, people still have the right to walk along the bed of the river.

Only federal courts can designate a river or section of a river navigable, the situation gets confusing when a state agency or commission holds hearings about public use of rivers.

It's been my experience that law enforcement officers have no clue on laws concerning rivers and usually side with property owners when a conflict occurs.

A good rule is that when fishing a non-navigable river is do not cross private property[ this applies to all fishing] or step out of a boat,anchoring can be a problem but I only know of one serious problem, it took place on the Trask in Or.

There's lot of info on various sites, makes for interesting reading.