The board of equalization may require the attendance of any county officer or deputy, who must furnish the board with any information which may be had from the records in his office and which the board may deem necessary in equalizing the assessments, and may also subpoena witnesses and hear evidence in all matters relating to the assessment of property, and may arbitrarily assess the property of any person refusing to appear or testify, and any assessment so made shall be conclusive on all questions of assessment in any court or proceeding.
Idaho Code § 63-505