The Lusk Strawn field straddles the Lea and Eddy county line, approximately 30 mi northeast of Carlsbad, New Mexico. It is a northwest-southeast-trending anticline with more than 650 ft of structural relief. The productive unit is primarily a biostrome at approximately 11,300 ft in depth. This biostrome is in the Middle Pennsylvanian Strawn Group. Bioherms grew on the west and north flanks of the feature. Porosity of the pay unit is intercrystalline and vuggy. The pay unit is extremely fractured, and these fractures have been important in the creation of porosity and permeability. To August 1, 1966, the field had produced 12,449,426 bbl of oil and 31,585,786 Mcf of gas from 61 wells draining approximately 10,400 surface acres. Because Lusk was developed on 160-acre spacin , allowables are high and payout is rapid. The discovery of this major field has stimulated deep drilling in the province in search of more Lusk-type production.