Shell Keys National Wildlife Refuge is located in the offshore waters to the west of the Atchafalaya River Delta, south of Marsh Island Wildlife Management Area.

[1] Due to coastal erosion, the refuge boundary is not well defined.

It has been described as "... a small group of unsurveyed islets located in the Gulf of Mexico about three and one half miles south of Marsh Island (Louisiana), and approximately at latitude 29 degrees 26 minutes north, longitude 91 degrees 51 minutes west from Greenwich..." The boundary of the refuge has been interpreted to be those areas in this vicinity that are above mean high tide.

Recent hurricanes and storms have eroded the island to such an extent that no nesting has occurred since 1992.

Public access to the refuge is restricted due to its remoteness.