Aguinaldo's party, traveling with del Pilar's force, reached Manaoag, Pangasinan on November 15. There, the force was split into vanguard and rear guard elements, with Aguinaldo and del Pilar in the vanguard. The vanguard force overnighted in Tubao, La Union, departed there on November 16, and was in Naguilian, La Union by November 19, where word was received that American forces had taken Santo Tomas and had proceeded to Aringay. Aguinaldo's force arrived in Balaoan, La Union on November 19, pushed on the next day, and arrived at the Tirad Pass, a natural choke point, on November 23. General del Pilar decided to place a blocking force in Tirad Pass to delay pursuing American forces while Aguinaldo's party moved on.