ABC7 News has been reporting on the fight over Drakes Bay Oyster Company since 2007.
The park service claims the farm in the Point Reyes National Seashore is harming the environment and wants it closed.
However, the National Academy of Sciences found the park service's environmental review lacks strong scientific support because there wasn't enough data available.
Interior Secretary Ken Salazar has the final say about Drakes and his decision is expected within the next few days.
Drakes has been in operation since 1934 and is the last cannery on the West Coast.