Landing Zone Sierra was a U.S. Marine Corps base located northwest of Cam Lộ, Quảng Trị Province in central Vietnam.

The base was located on Mutter's Ridge north of The Rockpile, approximately 16 km northwest of Cam Lo.

[2] On 2 March 1969 the 1st Battalion 4th Marines began Operation Purple Martin north of the Rockpile to engage the PAVN 246th Regiment which was believed to be located in the area.

[3]: 52  After retaking Landing Zone Mack, on 13 March the Marines moved along the ridgeline to retake Landing Zone Sierra which had been abandoned two months earlier and was now used by the PAVN to mortar Marines positions.

This article incorporates public domain material from websites or documents of the United States Marine Corps.