Idaho Code § 5-210
For the purpose of constituting an adverse possession, by a person claiming title not founded upon a written instrument, judgment or decree, land is deemed to have been possessed and occupied in the following cases only:
Provided, however, that in no case shall adverse possession be considered established under the provisions of any sections of this code unless it shall be shown that the land has been occupied and claimed for the period of twenty (20) years continuously, and the party or persons, their predecessors and grantors, have paid all the taxes, state, county or municipal, which have been levied and assessed upon such land according to law. Provided further, that adverse possession shall not be considered established under the provisions of any sections of this code if a written instrument has been recorded in the real estate records kept by the county recorder of the county in which the property is located and such written instrument declares that it was not the intent of a party to such instrument, by permitting possession or occupation of real property, to thereby define property boundaries or ownership. Provided further, that for purposes of establishing adverse possession pursuant to this section, a person claiming adverse possession must present clear and convincing evidence that the requirements of subsection (1) or (2) of this section have been met.
Idaho Code § 5-210