To the Taínos this area was known as the Higüey province and was the territory of a cacique named Cotubanamá (sometimes referred to as Cayacoa). But in 1503, Bartolomé de Las Casas destroyed much of the area, killing thousands of Taínos and their leader. By 1515 almost the entire population of Taínos was annihilated.
Researchers believe that this area (especially the Parque Nacional del Este [1]) was the site of a major community of Taíno Caribbean civilization. Deep in the forest of the national park, scientists have discovered ruins, artifacts, and cave drawings pointing to the settlement of Taínos that had once called the Southeast [2] home.
And although there is Spanish documentation of these early events, the cave drawings discovered tell important stories of the first interactions and subsequent altercations between the Spanish and Taíno natives from the Taíno perspective. Additional pictographs were found in the caves of the Parque Nacional Los Haitises [3].
Links:
[1] http://www.moon.com/destinations/dominican-republic/the-southeast/bayahibe/sights/parque-nacional-del-este
[2] http://www.moon.com/destinations/dominican-republic/the-southeast
[3] http://www.moon.com/destinations/dominican-republic/the-southeast/la-costa-esmeralda/parque-nacional-los-haitises