Many land rights and human rights activists gathered in front of Phu Khiao Prison in Chaiyaphum on Saturday morning to welcome Supap to the outside world after she completed her term for encroaching on Phusam Phaknam National Preserved Forest.
Afterwards, they performed a Thai traditional blessing ceremony for people who have overcome difficulties.
Supap, her husband, Den, and 10 other people were arrested for forest encroachment in July 2011. The Supreme Court later judged the couple guilty and punished them with six-month jail terms. Supap was imprisoned in July last year.
Den disappeared in April 2016. There has been no confirmation about his whereabouts, or whether he is alive or dead, and he is officially considered a fugitive. Many activists believe he is a victim of enforced disappearance.