All conservation futures on agricultural lands acquired pursuant to RCW 64.04.130 or 84.34.200 through 84.34.240, that are held by any nonprofit corporation or association, the primary purpose of which is conserving agricultural lands and preventing the conversion of such lands to nonagricultural uses, shall be exempt from ad valorem taxation if:

(1) The conservation futures are of an unlimited duration;

(2) The conservation futures are effectively restricted to preclude nonagricultural uses on such agricultural land; and

(3) The lands are classified as farm and agricultural lands under chapter 84.34 RCW: PROVIDED, That at such time as these property interests are not used for the purposes enumerated in RCW 84.34.210 and 64.04.130 the additional tax specified in *RCW 84.34.108(3) shall be imposed.

*Reviser's note: RCW 84.34.108 was amended by 1999 sp.s. c 4 s 706, changing subsection (3) to subsection (4).