South Korea’s military began its annual campaign of searching for Korean War-era remains at frontline battlefields nationwide Monday, despite North Korea’s continued absence from the effort.

Roughly 100,000 troops from 30 Army formations and the 1st Marine Division will be mobilized for the eight-month excavation effort this year, according to a Defense Ministry news release Monday. The project will focus on 34 sites across 22 cities and counties that saw heavy fighting during the 1950-53 Korean War. 

The campaign will be divided into two phases to account for seasonal conditions: March 9 to July 3 and Sept. 1 to Nov.