Mont. Code Ann. § 15-8-201 — General Assessment Day

15-8-201 . General assessment day. (1) The department shall, between January 1 and the first Monday of August in each year, ascertain the names of all taxable inhabitants and assess all property subject to taxation in each county.
(2) The department shall assess property to:
(a) the person by whom it was owned or claimed or in whose possession or control it was at midnight of the preceding January 1; or
(b) except in the case of land splits, the new owner if the provisions of 15-7-304 have been met and the transfer certificate has been received and processed prior to determining the taxes that are due as provided in 15-10-305 (2).
(3) The department shall also ascertain and assess all mobile homes arriving in the county after midnight of the preceding January 1.
(4) A mistake in the name of the owner or supposed owner of real property does not invalidate the assessment.
(5) The procedure provided by this section does not apply to:
(a) motor vehicles;
(b) motor homes, travel trailers, and campers;
(c) watercraft, snowmobiles, and off-highway vehicles;
(d) livestock;
(e) property defined as special mobile equipment in 61-1-101 that is subject to assessment for personal property taxes on the date that application is made for a special mobile equipment decal;
(f) mobile homes and manufactured homes held by a distributor or dealer as stock in trade; and
(g) property subject to the provisions of 15-16-203 .