Wyo. Stat. § 14-2-604

paternity.

     (a) An acknowledgment of paternity and a denial of
paternity may be contained in a single document or may be signed
in counterparts, and may be filed separately or simultaneously.
If the acknowledgement and denial are both necessary, neither is
valid until both are filed.

     (b) An acknowledgment of paternity or a denial of
paternity may be signed before the birth of the child.

     (c) Subject to subsection (a) of this section, an
acknowledgment of paternity or denial of paternity takes effect
on the birth of the child or the filing of the document with the
state office of vital records, whichever occurs later.

     (d) An acknowledgment of paternity or denial of paternity
signed by a minor and a legal guardian of the minor is valid if
it is otherwise in compliance with this act.