SDCL § 37-25A-39: Offers to sell accepted in this state.

For the purpose of this chapter, an offer to sell is accepted in this state if acceptance:

(1) Is communicated to the offeror in this state; and

(2) Has not previously been communicated to the offeror, orally or in writing, outside this state; and acceptance is communicated to the offeror in this state, whether either party is then present in this state if the offeree directs it to the offeror in this state reasonably believing the offeror to be in this state and it is received at the place to which it is directed or at any post office in this state in the case of a mailed acceptance.