Active Acquisition State
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Illinois has been producing oil since the early 1900s and was once one of the top oil-producing states in the country. Today, the Illinois Basin continues to produce from conventional reservoirs across the southern and southeastern parts of the state, with many fields in secondary recovery (waterflood) that extends production for decades beyond primary depletion. We buy mineral interests and royalties across the Illinois Basin, from small inherited interests to larger legacy holdings. While Illinois is not a high-growth drilling state, its long-lived production base generates steady royalty income for thousands of mineral owners, and the basin's mature geology means that production profiles are well-understood and predictable.
Highlighted state with approximate basin locations shown in tan
The table below shows the top producing counties in Illinois where we are most active, along with the primary operators and target formations in each area.
| County | Major Operators | Key Formations |
|---|---|---|
| White | Campbell Energy, Gallagher Drilling | McClosky, Aux Vases, Cypress |
| Wayne | Campbell Energy, Midwest Operating | McClosky, Salem, Aux Vases |
| Wabash | Trilogy Operating, Gallagher Drilling | McClosky, Cypress |
| Lawrence | Countrymark Energy, Ring Operating | McClosky, Robinson Sand |
| Crawford | Ring Operating, Gallagher Drilling | Robinson Sand, Casey |
| Clay | Midwest Operating, Campbell Energy | Cypress, Aux Vases |
| Marion | Campbell Energy, Midwest Operating | McClosky, Salem |
| Richland | Countrymark Energy, Gallagher Drilling | McClosky, Aux Vases |
The Illinois Basin is operated primarily by small, independent operators rather than the large companies that dominate the major shale plays. Campbell Energy, Countrymark Energy, Trilogy Operating, Gallagher Drilling, and Ring Operating are among the more active companies. Many Illinois oil fields are operated by family-owned companies that have been in the basin for generations. The small-operator nature of the Illinois Basin means that production data can be more dispersed and harder to aggregate than in states with concentrated operator bases, but it also means that the operators are deeply familiar with the specific geology and production characteristics of their fields.
Operators ranked by the number of Illinois counties where they hold the top active-well count. Counties where the operator runs the most active wells link through to the county detail page.
Illinois lease terms typically include royalty rates of 1/8 (12.5%) to 3/16 (18.75%), with 1/8 being the standard on most legacy leases. Illinois does not have a forced pooling statute, which means operators must negotiate leases with individual mineral owners. This can create complications when mineral interests have been fractioned over multiple generations of inheritance. Bonus payments for new leases in Illinois are generally modest. Many Illinois leases have been held by production for decades, and the lease terms reflect the era in which they were originally negotiated. Illinois does not impose a severance tax on oil and gas production.
We buy mineral interests, royalty interests, NPRI, and ORRI across the Illinois Basin's producing counties.
Not sure which type you own? Start with our mineral rights glossary for plain-English definitions of MI, RI, NPRI, and ORRI.
Illinois mineral interests have some unique characteristics. The state does not have a forced pooling statute, which means that highly fractioned mineral interests can be difficult for operators to lease. Illinois also has the Severed Mineral Interest Act, which allows surface owners to petition for mineral interests that have been severed for 20 years or more without any productive use. If you hold an Illinois mineral interest that has not been actively managed, it is important to verify your title and consider your options. The lack of a state severance tax is favorable for production economics.
Illinois mineral owners occasionally run into questions about severance-tax treatment, dormant mineral statutes, and non-participating royalty interests. These topics rarely drive a transaction, but understanding them helps you read a division order or evaluate an offer. The summaries below are starting points — verify against current statute text before relying on them.
Illinois has no severance tax on conventional oil and gas — long-running statutory exception. A small Hydraulic Fracturing Tax (5%-6% on gross value of fracked oil and gas) applies to qualifying high-volume hydraulic fracturing operations under the Illinois Hydraulic Fracturing Regulatory Act, but applies to very few wells in practice.
Illinois counties impose ad valorem property tax on producing minerals. The very low effective state-tax burden is partly a reflection of how mature and low-volume most Illinois Basin production is — most state revenue comes from county property tax, not severance.
Statutory citation: 225 ILCS 732 (HFRA), 35 ILCS 450 (severance)
Illinois has a Dormant Mineral Interest Act (765 ILCS 515/1 et seq.). After 25 years of non-use (no production, no lease, no recorded conveyance), the surface owner of the underlying tract may file a notice procedure; the mineral owner has a defined window to preserve the interest. Without preservation, the interest reverts to the surface owner.
Statutory citation: 765 ILCS 515/1 et seq.
Illinois recognizes NPRIs as cost-free royalty interests. They are subject to the same 25-year dormant mineral risk as other mineral interests under 765 ILCS 515/1 — unused NPRIs should be preserved through recorded use or Statements of Claim.
Need plain-English definitions? See our mineral rights glossary.
No. Illinois is one of the few producing states that does not impose a severance tax on oil and gas production. This means that production revenue is not reduced by a state severance tax before your royalty is calculated, which is favorable for mineral owners. You will owe federal and state income tax on royalty income and sale proceeds, but the absence of a severance tax makes the per-unit economics of Illinois production slightly more favorable than in states with severance taxes.
The Illinois Severed Mineral Interest Act allows surface owners to petition for severed mineral interests that have not been used for 20 years or more. The act requires the surface owner to follow specific notice procedures, and the mineral owner has the opportunity to preserve their interest by filing a claim. If you hold an Illinois mineral interest that has not been actively managed — no leasing, no royalty payments, no recorded documents — it may be at risk. We can help evaluate the status of your interest and potentially purchase it before any claim is filed.
Yes. While Illinois is not a high-growth drilling state, the Illinois Basin continues to produce over 20,000 barrels of oil per day from thousands of wells. Many fields are in secondary recovery (waterflood) operations that have been running for decades and will continue for decades more. The long-lived, steady nature of Illinois production means that mineral interests generate reliable royalty income even if the per-well volumes are modest.
Yes — Illinois has a compulsory integration statute (225 ILCS 725/22.2, Illinois Oil and Gas Act) administered by the Illinois Department of Natural Resources Oil & Gas Resource Management Division. It is used selectively given the basin's mature, conventional production base — most Illinois operators prefer voluntary pooling because lease bonuses are modest and units (typically 40 acres for conventional, larger for waterflood) are easy to assemble. IDNR issues integration orders after public hearings; non-consenting unleased mineral owners receive a 1/8 royalty, and non-consenting working-interest owners typically face a 200% risk penalty on out-of-pocket costs. See our /sell-mineral-rights/forced-pooling#illinois section for the full framework.
Illinois Basin mineral values are generally lower than in the major shale plays because production rates are lower and the play is mature. However, the steady, long-lived nature of waterflood production means that even modest royalty streams have present value. Small inherited mineral interests that generate a few hundred dollars per year in royalties are common and represent the majority of the interests we purchase in Illinois. We evaluate each interest based on its specific production data, decline characteristics, and remaining waterflood life.
See all mineral rights FAQ.
State-specific guides covering the legal mechanics that come up most often for owners considering a sale.