20-6-501. Definition of various schools. As used in this title, unless the context clearly indicates otherwise, the term "school" means an institution for the teaching of children that is established and maintained under the laws of the state of Montana at public expense. The trustees of a district shall designate the grade assignments for the schools of the district, but for the purposes of this title each school is known as:

(1) an elementary school when it comprises the work of any combination of kindergarten, other preschool programs, or the first eight grades or their equivalents. A middle school is a school comprising the work of grades 4 through 8 or any combination of grades 4 through 8 that has been accredited as a middle school under the provisions of 20-7-102. When an accredited junior high school is operated by the district, grades 7 and 8 or their equivalents may not be considered as elementary grades.

(2) a high school when it comprises the work of one or more grades of schoolwork or their equivalents intermediate between the elementary schools and the institutions of higher education of the state of Montana. Types of high schools are designated as follows:

(a) a junior high school is a school comprising the work of grades 7 through 9 or their equivalents that has been accredited as a junior high school under the provisions of 20-7-102;

(b) a senior high school is a school that comprises the work of grades 10 through 12 or their equivalents and that is operated in conjunction with a junior high school;

(c) a 4-year high school is a school comprising the work of grades 9 through 12 or their equivalents.