Private Water on the Snake River?

[Huntsy7]

Question? Just north of the Gem Lake recreation area boat ramp in Idaho Falls, There is a slough that branches off north east of the river that enters into a sub division that I have been thinking about fishing Via access by water with My Jet boat. Looking at GIS and ON-X maps its clear the ground the water covers is Private but Its my understanding that the Water and the Fish that reside on that property are public according to Idaho laws. The reason I ask is I have heard multiple reports of homeowners around the slough making threats of trespassing to anglers fishing from their boats and honestly I don't need to deal with that kind of BS while fishing so I want to get some feedback from you all on what the actual rules are. I appreciate the Help.
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