Mont. Code Ann. § 70-19-201
In actions respecting mining claims, proof must be admitted of the customs, usages, or regulations established and in force at the bar or diggings embracing such claim; and such customs, usages, or regulations, when not in conflict with the laws of this state or the United States, must govern the decision of the action.
History: En. Sec. 363, p. 139, L. 1877; re-en. Sec. 363, 1st Div. Rev. Stat. 1879; re-en. Sec. 375, 1st Div. Comp. Stat. 1887; amd. Sec. 1321, C. Civ. Proc. 1895; re-en. Sec. 6881, Rev. C. 1907; re-en. Sec. 9499, R.C.M. 1921; Cal. C. Civ. Proc. Sec. 748; re-en. Sec. 9499, R.C.M. 1935; R.C.M. 1947, 93-6223.