Mont. Code Ann. § 15-8-204 — Supplemental Assessment

15-8-204 . Supplemental assessment. When any personal property liable to taxation is brought into a county at any time after the first Monday of August and the property has not been assessed for that year, it must be listed and assessed the same as if it had been in the county at the time of the regular assessment, and the tax must be collected, as provided in this code, at any time.