SDCL § 33-1-14: Qualifications of staff officers--Term of office--Vacancies.

The staff officers of the Department of the Military, including authorized administrative assistants, shall have had previous military experience and shall hold their positions until they have reached the age of sixty years, unless retired prior to that time, by reason of resignation, disability, or for causes to be determined by a court-martial legally convened for the purpose; and vacancies in such offices shall be filled by appointment from the officers of the National Guard of the state.