S.D. Codified Laws § 32-29-3
The driver of a vehicle approaching a yield sign shall in obedience to the sign slow down to a speed reasonable for the existing conditions, or shall stop if necessary in a similar manner as provided in § 32-29-2.1, and shall yield the right-of-way to any pedestrian legally crossing the roadway on which he is driving, and to any vehicle in the intersection or approaching on another highway so closely as to constitute an immediate hazard. The driver, having so yielded, may proceed and the drivers of all other vehicles approaching the intersection shall yield to the vehicle so proceeding. A violation of this section is a Class 2 misdemeanor.
However, if the driver is involved in a collision with a pedestrian in a crosswalk or a vehicle in the intersection after driving past a yield sign without stopping, the collision is prima facie evidence of his failure to yield the right-of-way.
SDCL 32-29-3