SDCL § 59-7-9: Acts pursuant to durable power of attorney--Absent termination provision, authority not affected by time lapse since execution of instrument.

All acts done by an agent pursuant to a durable power of attorney have the same effect and inure to the benefit of and bind the principal and the principal's successors in interest as if done by the principal. Unless the instrument states a time of termination, the authority of the agent is exercisable notwithstanding the lapse of time since the execution of the instrument.