Marshall, Casey, Martinsville: we buy minerals and royalties throughout Clark County, the oldest oil ground in Illinois, on the La Salle anticline at Westfield and Siggins.
Clark County is where Illinois oil began. A gas well near Casey in 1904 and the Westfield discovery in 1905 set off the state's first boom, and Siggins once had an actual oil mine, with men underground collecting crude that seeped through the walls. What is left is a shallow, old, stripper county with a serious orphan well problem and thousands of small royalties held by people who have never been to Marshall.
What produces here. The Illinois Petroleum Resources Board puts Clark County at 183,468 barrels for calendar 2025, down from 192,778 in 2024. The oil comes from the dome fields along the crest of the La Salle anticline, Westfield, Siggins, Martinsville, Johnson North and South, Inclose, Casey, Oak Point and Weaver, with pay from Pennsylvanian sand at a few hundred feet through the Carper and St. Louis to the Trenton at about 2,300 feet; the ISGS database carries about 1,550 unplugged oil producer records here and Ashmore South is a gas storage field. The operators in the county records include Atlantis Energy, N and R Inc., Ashley Oil, Horizontal Systems, Huff Drilling, Max Knierim, Dover Illinois, Partlow Enterprises and Gary Energy. Drilling is minimal: the IDNR weekly permit logs show four oil well permits in 2025, N and R's Howard 5A to the Grand Tower at 1,700 feet in May, James Brian Ingram's Vincent Gard 1A to the Abbott at 575 feet in June, and Atlantis Energy's Ohme 2-C and 3-C to the Chouteau-Carper at 1,100 feet on December 22, 2025, and no permits in 2026 through late October. The bigger story is the orphans: IDNR data cited by the Chicago Tribune in May 2026 put the statewide count near 3,900 wells and the plugging bill around $155 million, and the paper's reporting on Fireball Production's 603 abandoned wells came from around Casey and Cumberland County.
Whatever you own here, producing royalties, non-producing acreage, or an inherited fraction split among family, we will identify it from whatever paperwork you have, value it off the actual wells and activity, and show you the reasoning with the offer. Free, no obligation, and no pressure: if keeping it is the right answer, we will say so. Inherited it? Start with inherited mineral rights in Illinois.
The dome fields on the crest of the La Salle anticline where Illinois' first boom started in 1904 and 1905: Westfield, Siggins, Martinsville, Johnson North and South, Inclose, Casey, Oak Point and Weaver.
At Westfield the pay stacks from Pennsylvanian sand at 280 feet through the Carper at 875 feet to the Ordovician Trenton limestone at 2,300 feet; the county's wells bottom in the St. Louis, Pennsylvanian, Carper, Trenton, Partlow and Devonian.
Wherever your tract sits in Clark County, we will research it free and value it with the work shown.
We buy in every Illinois county, including ones without a page here. See the full county index or the Illinois overview.
Whether you need a probate, the affidavit and transfer on death routes, the dormant mineral rules, and where unpaid royalties go: inherited mineral rights in Illinois, what heirs should do.
What Illinois mineral rights are worth, information only, with this month's activity. Unclaimed Illinois royalties: where the money goes and how an heir claims it.
Everything a Illinois owner needs in one place: who owns what under state law, how royalties must be paid and by when, what a buyer can and cannot deduct, the tax treatment of a sale, and the deadlines that quietly cost people their minerals. Free, and no sign-up.
Read the Illinois guideThe things owners here most often wish they had read first. All free, none of it gated.
Free, no obligation, and no pressure. We reply within one business day, usually faster.
Prefer the phone? Call or text 918-984-1645 and you will get Stephen, the owner, not a call center. If we miss you, we text back the same day.
In a hurry? Text a photo of a royalty check stub to 918-984-1645 and our preliminary offer puts a written number in front of you within about two business days. It holds for 7 while you decide.