048-5 Wyo. Code R. § 5-3
(a) The death certificate shall be filed with the local registrar of the county in which the death occurred within three (3) days of the date of death.
(b) When a death certificate cannot be completed within three (3) days of the date of death, the local registrar may grant an extension of time, not to exceed forty-eight (48) hours. In all cases a death certificate must be filed with the local registrar within five (5) days of the date of death.
(c) If the cause of death cannot be determined within the time limits specified above, the person responsible for the medical certification shall sign the certificate and mark the cause of death "Pending."
(d) If the funeral director is unable to obtain the personal information within the specified time limit, the certificate shall be filed with the information that is available.
(e) When an incomplete death certificate is filed, a supplemental report providing the missing information shall be filed with the State Registrar as soon as possible.
048-5 Wyo. Code R. § 5-3