Mont. Code Ann. § 1-1-501

The great seal of the state is as follows: a central group representing a plow and a miner's pick and shovel; upon the right, a representation of the Great Falls of the Missouri River; upon the left, mountain scenery; and underneath, the words "Oro y Plata". The seal must be 2 1/2 inches in diameter and surrounded by these words, "The Great Seal of the State of Montana".