SDCL § 36-13-1.3: Chain of title defined.

The term, chain of title, means all documents of conveyance given in a continuous succession of title:

(1) With respect to unplatted lands, the smaller of:

(a) Each quarter section of land; or

(b) If a patent was issued for a portion of quarter section of land, then that portion for which that patent was issued; and

(2) With respect to platted lands, a lot as shown on the last subdivision plat recorded against the property. However, if all documents transferring ownership and given in a continuous succession of title ownership from the present owner back in time to the recording of the subdivision plat combine more than one lot, then those multiple lots included in the documents of conveyance shall be considered one chain.

As used in this section, the term, lot, means the smallest intact areas into which land has been subdivided by a subdivision plat map, whether denoted a lot, parcel, tract, undivided block, or other similar designation.