When the April 3 Incident began, there was really no issues in Euigwi-ri (의귀리). When the May 10 General Election (5.10선거) rolled around, even though some young people boycotted the election and hid in the mountains, the police and army (South Korean Constabulary) was able to safely carry out the election and there were no major incidents, unlike in other parts of Jeju.

However, everything changed for Euigwi-ri after the evacuation order ( for the mid-mountain villages came in November 1948. On November 7, 1948 the armed resistance group launched a surprise attack on Seogwipo. In retaliation, suppression force raided Euigwi-ri, burning the village down and killing villagers. Most villagers fled into the surrounding area, but those who could not were killed. Over the next two months many more people were killed at and around Euigwi Elementary School (where the army had established a base). On January 10 and 11, 1949 20 some odd people were killed here.

This prompted a response from the local armed resistance group who plotted a surprise early morning attack on the school on January 12, 1949. However, the army had anticipated this attack and they were prepared. After an approximately two hour fight, the armed resistance retreated, but not before 51 members were killed and they lost several rifles and ammunition.

The people (residents) who had been killed were buried in various areas around Euigwi-ri, and later the remains were excavated and moved to Hyuneui Habhang.

References

Jeju 4.3 Archives - "현의합장모역" (readable here in Korean)

Jeju Dark Tours - "Hyeonuihapjangmyo (graveyard)" (readable here in English)