Idaho Code § 63-2803: Statement of net profits.

Every person, corporation or association engaged in mining upon any quartz vein or lode, or placer mining claim, containing gold, silver, copper, lead, coal or other precious and valuable minerals or metals, or mineral or metal deposits, must, between the first day of January and the first day of May in each year, make out a statement of the net profits derived from the mining of said metals or minerals, from each mine or mining claim owned or worked by such person, or from each group of mines or mining claims worked by a common system of development, during the year preceding the first day of January. Such statement must be verified by the oath of such person, or superintendent or managing agent of such corporation or association, who must deliver the same to the assessor of the county in which such mines are situated.