Soil gas studies were undertaken to investigate the existence of cross-strike discontinuities (CSD's), in a portion of the Bass Island oil and gas reservoir in Western New York State. The Bass Island structural trend is a complex fracture system with cross-strike discontinuities that cross the major trend of thrust faults. The locations of CSD’s are important in the location of natural gas and oil because they offset the major structural trend and potentially provide a seal between sections of the Bass Island Trend. It is known that open fractures can provide preferential pathways for the migration of thermogenic gases, primarily methane and ethane, to the surface. Data from geochemical analysis at the surface define gas anomalies that suggest the existence of open fractures, potentially allowing detection of the Bass Island Trend if structure associated with the trend reach the surface. There was over 4,800-soil gas samples were collected from 28 different traverses totaling 113,930 feet / 34,725 meters, resulting in the delineation of 7 CSD's. The results from this study have demonstrated the usefulness and applicability of soil gas analyses in locating and characterizing CSD’s related to oil and gas prospects along the Bass Island Trend.