Mont. Code Ann. § 75-5-904
Applicability to counties -- notification
75-5-904 . Applicability to counties -- notification. (1) The provisions of 75-5-905 apply to counties where one or more surface water bodies exceed the numeric algal biomass or total phosphorus standards adopted pursuant to 75-5-301 .
(2) The department shall notify counties that meet the provisions of subsection (1) that they are subject to the provisions of 75-5-905 .
(3) The governing body of a county that does not meet the provisions of subsection (1) may adopt an ordinance pursuant to Title 75, chapter 7, part 4.