This investigation specifies and estimates regression models to test several hypotheses about the operational and managerial drivers of HSE incidents with emphasis on the identification of potential leading indicator variables. A leading indicator, or precursor, provides a signal of an increase in the likelihood of HSE incidents for future activity. The results of this investigation suggest several viable candidates for precursor variables in onshore drilling, including impending rig moves, changes in supervision, and operator-contractor cumulative experience. The results empower engineering and operations personnel to intervene and initiate mitigation activities. While the investigation was completed for one operator in one geographic area, it is believed the results are generally applicable to other regions, other operators, and very likely to similar industrial sectors.