in any easement, grant, or assistance programs administered by that Secretary’s department. Participation in any such program pursuant to this section shall be voluntary. (e) Definitions In this section: (1) Military installation The term military installation has the same meaning as provided in section 670(1) of title 16, United States Code. (2) State-owned national guard installation The term State-owned National Guard installation has the same meaning as provided in section 670(3) of title 16, United States Code. (3) Sentinel landscape The term sentinel landscape means a landscape-scale area encompassing— (A) one or more military installations or state-owned National Guard installations and associated airspace