The South Arkansas Basin is the oil province of the state's southern tier, where Jurassic and Cretaceous rocks dip south toward Louisiana. It opened on January 10, 1921, when Dr. Samuel T. Busey brought in a well near El Dorado in Union County. Smackover followed on April 14, 1922, with a discovery well that found the Upper Cretaceous Nacatoch sand at about 2,024 feet, and within a year nearly a thousand wells had produced some 25 million barrels. The Magnolia field came in during March 1938 in Columbia County and became one of the state's most important fields during the early years of World War II. We buy mineral rights, royalty interests, NPRI, and ORRI across the South Arkansas Basin.
Approximate location of the South Arkansas Basin shown in tan
Basin-level activity chart not yet available for the South Arkansas Basin. For current activity, see our rig count dashboard and the state production pages linked above.
South Arkansas sits on the updip northern edge of the Gulf Coast section, where the sedimentary column thickens southward toward Louisiana. The key deep reservoir is the Upper Jurassic Smackover, an oolitic and silty limestone that produces oil across Arkansas, Louisiana, Texas, and the eastern Gulf states and that also holds an unusually concentrated brine. Shallower Cretaceous sands account for much of the rest: the Nacatoch, which the 1922 Smackover discovery well found at roughly 2,024 feet, along with the Meakin and other locally named intervals. Because the productive section runs shallow to moderate in depth, wells here are comparatively inexpensive to drill and work over, which is a large part of why so many of them have kept producing for the better part of a century.
The South Arkansas Basin is worked almost entirely by independents, many of them Arkansas and Louisiana companies that have specialized in these fields for generations. Wells are shallow, low-rate, and frequently supported by waterflood, so the operating model rewards low cost and long patience rather than growth drilling. Alongside the oil operators sit the brine producers. Union and Columbia counties together hold what is described as the largest bromine reserve in the United States, and Albemarle runs bromine product facilities in the Magnolia area. More recently the same Smackover brine has drawn lithium developers, with a 2024 federal and state announcement pointing to a very large lithium resource in the formation. Two industries now draw on one interval.
Value in south Arkansas comes from long life rather than high rates. A typical producing interest here is a small, steady royalty from wells that have been on production for decades and are supported by waterflood, so buyers price the remaining tail, the operator's cost structure, and the plugging horizon. Interests in and around El Dorado, Smackover, and Magnolia are the most actively traded. The wildcard is brine. Bromine has been produced from Smackover brine for many years, and lithium development has brought new capital to the same interval, so owners increasingly ask whether their deed reaches the brine as well as the oil and gas. That question is worth answering before you sell anything.
That is a separate legal question from your oil and gas rights, and it is one a qualified Arkansas attorney should answer for your specific deeds. Arkansas has a long history of brine production from the Smackover, and instruments in a given chain of title vary widely in how they describe what was conveyed or reserved. Some speak broadly of all minerals; others are much narrower. Because brine development has attracted significant new investment, the wording in your documents may matter more now than it did when they were signed. We will tell you what we see in the record, and we will encourage you to get Arkansas counsel before relying on any reading of it.
More than most owners expect. The fields around El Dorado, Smackover, and Magnolia have been producing since the 1920s and 1930s, and waterflood and other secondary recovery have carried many of them far past their primary decline. For a royalty owner that means a modest check that has been arriving for a long time and will likely keep arriving for a while yet. It also means the value sits in the remaining tail rather than in any expectation of a new drilling boom. We price these interests on what the wells are actually doing today, not on a growth story.
The discovery well near Smackover in Union County came in on the Upper Cretaceous Nacatoch sand at about 2,024 feet, which is far shallower than the Jurassic Smackover limestone that later carried the Smackover name across the Gulf Coast. Within a year nearly a thousand wells in the area had produced roughly 25 million barrels. The distinction matters for owners, because an interest here may cover shallow Cretaceous sands, the deeper Smackover limestone, or both, and those are valued differently. When we review your interest we identify which zones are actually producing beneath your tract before we quote a number.