서산에 삼림조합이 조직된 것은 1925년경이었던 것으로 보이며 같은 해 12월 기준 전국의 삼림조합 수는 384개였다.
It seems that the forest association was organized in Seosan around 1925. In December of the same year, there were 384 forestry associations a nationwide.