Hi Gang,
I spoke with the Pennington County Treasurer's Office. Here is the word I received directly from their representative. They will accept out-of-state checks, delivered in person, bearing the South Dakota address. If the check is printed with an out-of-state address, the Treasurer's Office will cross-out that address and write-in the South Dakota address. Please know the Treasurer's Office will ask to verify your identity via a state or federal ID (e.g. driver license or passport.)
If the Treasurer's Office receives the funds via mail, (not in-person), then out-of-state checks may not be accepted. This policy gives rise to the well-discussed use of certified checks (or electronic payments afforded via on-line registration.) Why the difference in process; I hear you cry? As was explained to me, the Treasurer's Office is not able pursue the prosecution of one who gives them a bad check unless they (the Treasurer's Office) can attest to having verified the identity and signature of the person authoring the check. As such verification is not practical via the mail, the Treasurer's Office is relegated to only accepting certified checks, where payment is assured.
I hope this clarifies the issue.
(Also, Twotoes. I owe you personal apology. I never received your phone message which is why I did not respond. I'm looking-into why.)