It's always interesting to see the differences in attitudes between westerners and easterners/southerners.
Here in Mississippi all private land is considered posted unless you have written permission from the landowner to be on it, no posted sign required and no boundary marking required. It's the responsibility of the person to know where they are at all times. In practicality it's never going to become an issue unless the landowner decides to prosecute but it relieves the landowner of the burden of having to put up posted signs to legally keep people off his property.
I like it that way, it should be the responsibility of an individual to know where he is, a landowner shouldn't have to be proactive to keep trespassers off his property. That's like a burglar claiming he's got a right to break into your house because you don't have a sign stating otherwise and bars on your window.
Did you take look at the map RockChuck posted? That is typical Idaho (and other western states). Lots of landholdings bordering or surrounded by public land. Yes, we are different from the east.
