Earthquake source parameters, broadly defined as stress drop, rupture radius, rupture duration, radiated energy, etc., are important parameters that link earthquake rupture processes, high-frequency ground motion, and stress distributions in the subsurface, which can be linked with operation parameters during hydraulic fracturing. A detailed analysis of microseismicity source parameters is performed to a legacy dataset of four hydraulic fracture treatments of the Cotton Valley formation in 1997 at the Carthage gas field of east Texas. We analyze magnitude-frequency distributions of each stage and apply empirical Green’s function (EGF) analysis to estimate corner frequency and stress drop by removing the influence of path effect from the recorded seismogram. These results will be used to evaluate the differences in stress distributions within fractures created during operation and pre-existing optimally oriented fractures.