Hello, and welcome to the forum!
This topic might be better suited for the General Discussion Forum.
A short typical PNW synopsis might be
For books maybe the story of Gifford Pinchot, founder and first chief of the Forest Service, under President Theodore Roosevelt.
"Gifford Pinchot and the First Foresters: The Untold Story of the Brave Men and Women Who Launched the American Conservation Movement"
by Bibi Gaston
"The Big Burn: Teddy Roosevelt and the Fire that Saved America" by Timothy Egan
"Natural Rivals: John Muir, Gifford Pinchot, and the Creation of America's Public Lands" by John Clayton (
preservation vs
. conservation)
Reasons fishing/swimming/hiking spots aren't open for public can be a conflict with an owner's use, another public use, safety, and just the costs associated with allowing the public to be there that includes routine upkeep-maintenance,
and loss of use plus repair of resources after abuse like littering, destruction of trees, and other vandalism. There are also liability costs for corporate and private owners.
A simple way to determine ownership is to get a subscription mapping program that runs on a computer for online research and planning at home, then syncs to a mobile device for offline use in the field like "Gaia", "onX". They have an ownership "layer" showing public (Federal, State, Local) & private property boundaries that overlays onto their basemaps containing the roads, trails, rivers, lakes... we are interested in. I haven't used "onX" but know that Gaia has a subscription for worldwide maps with points of interest data for hiking, fishing, hunting, offroad... activities I want for about the same cost onX charges for one state and one activity.
Once you know the ownership then you can do the research to find out if you can access it. That may involve going to a government or corporate website to find out if public access is allowed and any conditions required for access like passes and permits. It may also mean knocking on doors to meet and ask a private property owner.
Also, even if a river flows through private land you may still be able to fish it due to it being currently or in the past used for interstate-international commerce that would be considered "navigable waters". But that's a whole 'nother discussion.