SDCL § 25-4-45: Child custody provisions--Modification--Preference of child.

In an action for divorce, the court may, before or after judgment, give such direction for the custody, care, and education of the children of the marriage as may seem necessary or proper, and may at any time vacate or modify the same. In awarding the custody of a child, the court shall be guided by consideration of what appears to be for the best interests of the child in respect to the child's temporal and mental and moral welfare. If the child is of a sufficient age to form an intelligent preference, the court may consider that preference in determining the question. As between parents adversely claiming the custody, neither parent may be given preference over the other in determining custody.