SDCL § 62-8-45: Agreements between employer and employee.

If the employer and employee reach an agreement in regard to the compensation under this chapter, a memorandum thereof shall be filed with the department by the employer or employee, and unless the department shall, within twenty days, notify the employer and employee of its disapproval of the agreement by registered or certified letter sent to their addresses as given in the memorandum filed, the agreement shall stand as approved and be enforceable for all purposes under the provisions of this chapter.