2008 The Indonesian Gibbon Foundation and Kobus Foundation involved in Primate Helping Primate Program.
2009Orangutan Outreach with COP, JAAN and Kobus Foundation work together as an Orangutan Team. Since there was not legal cooperation between this team and government agency yet, the orangutans then transferred to International Animal Rescue in Ketapang, West Kalimantan.
2010 The Head of West Kalimantan BKSDA Office asked for legal cooperation to rescue, rehabilitate and release orangutan. Legal cooperation between Kobus Foundation and BKSDA announced.
2010-2015 Kobus Foundation agreed to develop Sintang Orangutan Center Programm that focusing on rescue, rehabilitate and release orangutan. Hasudungan Pakpahan became the SOC Programme Manager.
2015 Establish Yayasan Penyelamatan Orangutan Sintang as an independent organisation, separate management from Yayasan Kobus, that responsible in continuing and developing SOC Programm
2014 Opening Tembak Forest School. So far, Xx17 orangutan individuals have been schooled here
July 13th 2017 MoU (Agreement) between YPOS with Betung Kerihun National Park regarding to Orangutan Release Program have been signed. The National Park agreed to provide their area as the releasing site for orangutan from YPOS.
June – September 2017 Develop Release basecamp site and prepare all equipment at Mendalam River
November 2017 Jojo, Juvi and Cemong, the first three orangutans have been released at Betung Kerihun National Park, Mendalam river, Rongun.
April 19th 2018, Joy, Molly and Bembi have been released at the same site as the first released
October 22nd 2018, the second orangutan’s Forest School in Jerora officially run
October 25th 2018, YPOS released wild adult male orangutan more upstream from the previous releases.