Colombia’s recent oil boom, which began in about 2003, features the notable achievement of making Colombia one of the few countries in the world to surpass past oil peaks (i.e., maximum historical oil production), a phenomenon that among the western countries only the United States has approached with the shale/tight oil boom. In the 1990s, after the discoveries of Cusiana, Cupiagua (Cazier et al., 1995; Cooper et al., 1995) and other oil fields, Colombia reached a maximum daily production of about 830,000 BOPD in 1999, but soon afterwards started a steep decline. However, after 2003 daily production reached a minimum of 541,000 BOPD and started to grow steeply again in 2007 until past peaks in oil production were surpassed in 2011. During the 1990s peak as well as the current maximum the key component of Colombia’s oil production has come from the Llanos basin and associated eastern foothills, which ranked as the fourth most favorable basin in the world in terms of exploration success rate (IHS, 2010). However, until now there has been no comprehensive published study that explains this success or predicts the potential for finding future accumulations. In this special issue, we intend to provide the first comprehensive view of the Llanos basin and the adjacent hinterland of the Eastern Cordillera with the ultimate goal of explaining the existing accumulations and predicting the potential for new ones, to the extent allowed by the confidentiality of the organizations involved. Reyes-Harker et al. (2015, this issue) present the first paleogeographic reconstruction of the Llanos and Eastern Cordillera, including for the first time the most detailed and recent data regarding the uplift history of the Eastern Cordillera (i.e., Mora et al., 2008, 2010, 2013a, b; Parra et al., 2009a, b, 2010, 2012; Horton et al., 2010a, b …