Anse la Butte is on the west border of St. Martin Parish, Louisiana, in the south-central part of the state, within the belt of Gulf Coast salt domes. Drilling leading to the discovery in 1901 of shallow production and domal material was prompted by the presence of gas seeps and surface relief. Deeper flank production was discovered by Glassell and Glassell in 1940 following subsurface study and geophysical work. The production is from sands ranging from Pleistocene to Chickasawhay Miocene in age, with principal production from the upper Catahoula Miocene. Oil accumulation is found at depths from a few hundred to below 9,000 feet depending on structural position.

It is a piercement-type dome with salt found as shallow as 160 feet. Formational dips around the salt plug range up to 75°, being nearly everywhere slightly less than the surface of the contiguous salt mass. Strong radial faulting is noted.

Through August, 1942, 4,269,264 barrels of oil had been produced, with a total ultimate recovery indicated, from sands now known, of about 32 million barrels. Development of flank sands at shallow and intermediate depths is now probably complete, but recent drilling suggests the possible presence of additional deeper flank reserves.