Mont. Code Ann. § 70-15-103
Fixture defined
70-15-103 . Fixture defined. A thing is deemed to be affixed to land when it is:
(1) attached to it by roots, as in the case of trees, vines, or shrubs;
(2) imbedded in it, as in the case of walls;
(3) permanently resting upon it, as in the case of buildings; or
(4) permanently attached to what is thus permanent as by means of cement, plaster, nails, bolts, or screws.