The International Boundary and Water Commission, U.S. Section (USIBWC), has constructed the Land Outfall (LO), a 12,300 linear foot (3,749 m), 144-inch concrete pipeline in the Tijuana River valley. The purpose of the pipeline is to transport treated sewage from the USIBWC International Wastewater Treatment Plant (IWTP) to the Ocean Outfall (OO), both of which are yet to be constructed. Treated effluent will pass from the plant through the LO into the OO and into the Pacific Ocean. As with the IWTP, the OO has not been constructed. Construction is complete on the 144-inch LO pipeline. Archaeological monitoring of activities associated with construction of this pipeline are described in this report. The results of previous monitoring and some salvage excavations conducted by the U.S. Army Corps of Engineers, Los Angeles District (COE) are also described here. Finally, for completeness, results of archaeological testing along part of the reach are summarized herein.