S.D. Codified Laws § 2-12-1
Any person who employs any other person to act as a lobbyist to seek the introduction of legislation or to promote, oppose, or influence in any manner the passage by the Legislature of any legislation affecting the special interests of any agency, individual, association, or business, as distinct from those of the whole people of the state, or to act in any manner as a lobbyist in connection with any such legislation, shall register the name of the person so employed or agreed to be employed, with the secretary of state, to be included in a directory of registered lobbyists as hereinafter provided. The lobbyist shall also register with the secretary of state. Upon the termination of such employment prior to the adjournment sine die of a legislative session, such fact shall be entered opposite the name of any person so employed, either by the employer or employee.
SDCL 2-12-1