In idaho you can get your game if it's on private property. It's a good idea to let the landowner know what you're doing, and if there is a problem we're supposed to call F&G or the sheriffs office who will then show up and monitor your finding your game.
The Kalifornia info on tresspasing is here
http://www.dfg.ca.gov/docs/06-07_Mammal_Hunting.pdf
TRESPASING: If the land you hunt on is not your own, it belongs to someone else.
Make sure you have a legal right to be there. Contact the owner or person who administers the property, and secure written permission to hunt. A hunting license does not entitle you to enter private property.
“It is unlawful to enter any lands under cultivation or enclosed by a fence, belonging to, or occupied by, another, or to enter any uncultivated or unenclosed lands, including lands temporarily inundated by waters flowing outside the established banks of a river, stream, slough, or other waterway, where signs forbidding trespass are displayed at intervals not less than three to the mile along all exterior boundaries and at all roads and trails entering such lands, for the purpose of discharging any firearm or taking or
destroying any mammal or bird, including any waterfowl, on such lands without having first obtained written permission from the owner of such lands, or his agent, or the person in lawful possession thereof. Such signs may be of any size and wording, other than the wording required for signs under Section 2017, which will fairly advise persons about to
enter the land that the use ot such land is so restricted.” (FGC 2016)