The mortgagee, if the mortgaged property or part thereof consists of unpatented mining claims, may perform the annual labor or improvement, or pay the maintenance fees required by law to prevent the forfeiture of the claim, and the amount expended for that purpose shall be an additional debt secured by the mortgage, and included in the judgment of foreclosure, or, if expended after judgment, but before sale, added to the amount of the execution.
A.R.S. § 33-704