What was the purpose and mission of the Rocky Flats site?

The Rocky Flats Plant was part of the nationwide nuclear weapons complex. It manufactured radioactive and non-radioactive metal parts, primarily for nuclear weapons, from 1951 to 1989. Plutonium pits for U.S. nuclear weapons were produced at Rocky Flats between 1954 and 1989. Prior to 1954, pits were manufactured at Los Alamos National Laboratory and in1996, limited pit production resumed there.  
The site mission was changed in 1992 to decontamination and decommissioning of nuclear facilities, and cleanup and closure of the entire site.
Aerial view of Rocky Flats in 1995