Oil and gas exploration in the Hagan embayment of the Espanola Basin
— Bruce A. Black

The first oil and gas test drilled in the Hagan embayment was spud in 1954. No additional activity took place for the next 26 years. More recent oil and gas exploration in the Hagan embayment, inspired by oil shows seen in uranium core holes and surface indications of oil, began in the mid 1970s (Black, 1979a). In the intervening 23 years, 12 oil and gas tests have established the presence of source rocks, maturity, reservoir quality rock and probable traps in the area. Future exploration, utilizing the existing well control and additional seismic, will find both stratigraphic and structural trap potential in this unique and underexplored sub-basin of the Española basin in the Rio Grande rift.