Subsequently, since 1982, R. Joussaume had undertaken systemic excavation at Tiya and the results of his meticulous work has become significant for megalithic tradition in the region. Cloud Bouville, an anthropologist and director of research at CNRS, Marseille, excavated 45 tombs, which include 54 skeletons. Out of these, 35 of them are men and the rest female. The fossils dated in France in radiocarbon dating 12^th -14^th century AD.

In 1998, a restoration team led by Bertrand Poissonnier re-erected the stelae of Tiya that had been fallen down since unidentified period, because of undisclosed reasons. Poissonnier proposed the founding of a megalithic museum at Tiya.

Yonas (et al 1999), in their report to ARCCH, confirm the presence of 26 megalithic sites (including the famous site of Tiya) between Buye and Lemen towns in Soddo Wereda. Sites under family protection seem to be relatively well preserved as they are inaccessible to others. However, the report reveals that the stelae are undergoing an increasingly serious destruction due to manmade and natural factors. The report also gave emphasis to the foundation of a megalithic museum at Tiya, which will represent a single cultural tradition that was stretched in south-central Ethiopia.

In 2003, Roger Joussaume, in his report addressed to ARCCH, emphasizes the importance of the translation of his book “Tiya, lÉthiopie des megaliths “published in France in 1995 into English. In the same report, Joussaume proposed the listing of seven new sites that are found within Soddo on the World heritage together with the site of Tiya. He further suggests that for each site restoration with limited excavation, protection, maintenance and surveillance and explicative board.

In 2006, Claude Tournemire, based on Joussaume’s suggestion, travelled through Soddo and recorded about 30 stelae sites with GPS and photographs.

Worku Derara (2006) in his unpublished MA thesis entitle “An Inventory of Megalithic Sites in Gurage Highlands” revisited some of the sites revisited by Yonas et al (1999), Joussaume (2003) and Tournemire (2006) and counted and recorded the sites.

Hailu Zeleke, in 2006-2007, had conducted field surveys in Tiya and its environs and collected data, which are supposed to be the bases for future management plan for Tiya WHS.  Hailu Zeleke, in his “Yetiya mekane Kirs Asetedader Sened” (A Preliminary Management Plan for Tiya WHS) also state that the established a management committee for the Tiya WHS is still functional in day-to-day activities of the site.