RCW 84.36.630: Farming machinery and equipment.

(1) All machinery and equipment owned by a farmer that is personal property is exempt from property taxes levied for any state purpose if it is used exclusively in growing and producing agricultural products during the calendar year for which the claim for exemption is made.

(2) For purposes of this section, "farmer" and "agricultural product" have the same meaning as defined in RCW 82.04.213.

(3) A claim for exemption under this section must be filed with the county assessor together with the statement required under RCW 84.40.190, for exemption from taxes payable the following year. The claim must be made solely upon forms as prescribed and furnished by the department.