Orphan Oil and Gas Wells in the US, by State

The newest federal count is 130,121 documented, unplugged orphaned oil and gas wells in 28 states, from the U.S. Geological Survey’s Documented Orphaned Well Database 2026, published September 30, 2026. The states that answer the Interstate Oil and Gas Compact Commission (IOGCC) survey counted 141,959 at the end of 2023. Neither number is wrong. Each state decides what “orphaned” means, and the two compilations ask different questions.

Four states hold 61% of the USGS total: Ohio (22,759), Pennsylvania (21,262), Oklahoma (19,981) and Kentucky (15,638). Texas had 31% of the nation’s producing wells in 2024, 3.3 times as many as the next state, yet ranks fifth for orphans with 8,998. The 14 states with fewer than 1,000 orphaned wells hold 4,140 between them. A “documented” well is one on a state or federal list with a location. States estimate that another 250,000 to 740,000 orphaned wells are on no list at all, so no figure below is a census of every abandoned hole in the ground.

Six national counts and what each measures

Between 2020 and 2026 at least six numbers circulated for the size of the US orphaned well problem, five of them national totals running from 92,202 to 141,959. They are not a time series of one quantity. They differ in who counted, on what date, in how many states, and in whether a well needed coordinates to qualify.

The IOGCC figure rose 54% between 2020 and 2023, from 92,202 to 141,959, in a period when the states also plugged 14,580 orphan wells. IOGCC’s own explanation is that the growth is mostly documentation: “The biggest portion of the recent increases in state numbers reflects the efforts of the states to document their orphan wells.” The report adds that states have refined their criteria for orphan status, verified operators and well records, and confirmed locations by field inspection and drone surveillance. A larger number therefore means a better inventory at least as much as it means more abandoned wells.

Interior says as much in its fiscal 2025 report to Congress, published in November 2025: “While multiple organizations have developed their own estimates, a comprehensive national inventory of orphaned wells has not been established.” It continues: “The absence of a standard definition for ‘orphaned’ wells contributes to inconsistencies in reporting and complicates efforts to assess the true scope of the issue.” The same report notes that Interior and USGS were working to refine the national count by updating the 2022 dataset, which is the release dated September 30, 2026 that supplies the headline here.

The federal-lands row is a different kind of number. Interior’s fiscal 2024 report says its most recent inventory identified nearly 16,000 orphaned wells on federal lands, citing testimony to a House subcommittee on March 31, 2022. The report does not say how that inventory overlaps with the state lists, so the page does not add it to anything else.

What federal law leaves to the states

The 2021 Infrastructure Investment and Jobs Act created the grant programs, and its definition is codified at 42 U.S.C. 15907(a)(5). For state and private land, the statute does not set a national test. The term “orphaned well” with respect to State or private land “(i) has the meaning given the term by the applicable State; or (ii) if that State uses different terminology, has the meaning given another term used by the State to describe a well eligible for plugging, remediation, and reclamation by the State.” For federal and Tribal land the statute gives its own test, summarized here: a well that is not used for an authorized purpose such as production, injection or monitoring, and either has no locatable operator, has an operator unable to plug it and to remediate and reclaim the site, or lies within the National Petroleum Reserve in Alaska.

Interior’s November 2025 report restates the split: “Under the IIJA, orphaned wells are generally defined as wells not used for an authorized purpose and for which no operator can be located, or where the operator is unable to plug the well and restore the site. States may apply their unique state definitions for orphaned wells on state and private lands.” The statute also ties money to the lists. The formula that sets each state’s grant accounts for job losses and for the number of documented orphaned wells in the state and the projected cost of plugging and reclaiming them, and a formula application must describe the definitions and processes the state uses to identify a well as orphaned. The money therefore follows the state lists, and for state and private land the statute sets no common rule for what goes on them.

A separate statutory term shows why “orphaned” cannot be swapped for “idle.” The same section defines an “idled well” as one that has been nonoperational for not fewer than 4 years and has no anticipated beneficial future use. That definition does not mention an operator at all. The 2026 database abstract describes the criteria USGS uses: the database includes wells “where the state indicates that the well is an unplugged orphan, or the following criteria are met: 1) no production for 6 to 24 months depending on the state (an average of 12 months), 2) the well is unplugged, 3) there is no responsible party to manage the well for future re-use or for plugging and abandonment, and 4) the location of the well is documented.” The 2022 data report explains the fallback: where a state-provided orphan list was not available, the authors applied the criteria to the state’s well data and marked those states in its table.

Where a state keeps a list it calls orphaned, then, USGS takes the list. Table 2 shows what each of the 28 state lists in the 2026 database is, as USGS describes its collection method in the metadata.

The selection column makes the point better than any definition. Texas, with 8,998 wells, uses the Railroad Commission’s list of “Orphan Wells with Delinquent P-5 Greater Than 12 Months”, which the commission describes as “inactive, non-compliant wells that have been inactive a minimum of 12 months and the responsible operator’s Organizational Report (Form P-5) has been delinquent for greater than 12 months.” New Mexico’s 3,366 are every inactive well at 15 months of inactivity, a filter the state itself uses to report potential orphans. New York’s 7,600 are wells whose status is unknown. Alabama, Nebraska, Nevada and North Dakota are drawn from an abandoned status (North Dakota’s status is defined as abandoned, shut in for more than 12 months), Kansas from an abandoned well status report, and West Virginia from abandoned wells with an unknown operator. Louisiana, Michigan and Mississippi use a formal orphan status. A state-by-state ranking therefore ranks the lists as much as the wells.

The records are also uneven in what they say about each well. Eight states supply no well type for any record (Ohio, Texas, Kansas, West Virginia, Indiana, Tennessee, Arizona and Wyoming), and 42,825 of the 130,121 records (32.9%) have no type at all, so the database cannot reliably say how many orphaned wells are oil, gas or injection wells. The status field is the state’s own text. Fourteen records carry a status that reads “Plugged & Abandoned” or “P&A” (nine in Alaska and five in Oklahoma), so the status wording is each state’s, passed through unchanged. The USGS metadata describes the approach: inconsequential differences from source to source “were not reformatted in order to keep the data in a state as close as possible to that of the original source.”

Orphaned wells by state, 2026 database

Table 3 gives every state in the 2026 database, ranked by documented wells, beside its count in the 2022 edition. The totals match the published ones: 130,121 wells in 28 states and 117,672 in 27.

The concentration is steep. Four states have more than 10,000 wells (Ohio, Pennsylvania, Oklahoma and Kentucky), ten have between 1,000 and 9,999, seven have between 100 and 999, and seven have fewer than 100 (Utah 90, Montana 61, Alaska 44, Nebraska 32, Alabama 31, Mississippi 11 and Nevada 6). The USGS authors made the same observation about the 2022 data: higher orphaned well counts are recorded in the eastern and midwestern states, where oil and gas exploration got an earlier start, and they link that to a time in the second half of the 19th century when record keeping was less regulated. The 2026 ranking has the same shape at the top, with Ohio, Pennsylvania and Kentucky among the four largest. Oklahoma and Texas, third and fifth, sit outside that description.

The database is a composite of state snapshots, not a single count on a single day. Twenty state files are dated in 2025, six in 2026 (Ohio, Pennsylvania, Oklahoma, Kansas, New Mexico and Arizona), and two are older: California (2023-12-31) and Alaska (2024-04-02). A state that plugged wells in 2026 will not show it here until its next file, and a state that documented new wells will not either. That is one reason a published total should always carry a date, and the reason the headline of this page quotes the release rather than saying how many wells “exist.”

What changed from the 2022 edition

The 2026 database lists 12,449 more wells than the 2022 edition, a rise of 10.6%. That net change hides large movements in both directions. Of the 27 states in both editions, fifteen rose by a combined 20,110 wells and twelve fell by a combined 8,121. Arizona, which was left out of the 2022 edition, adds 460. The sum is 20,110 minus 8,121 plus 460, or 12,449. The five largest increases are Oklahoma (+4,010), Texas (+3,144), Kentucky (+2,943), New Mexico (+2,714) and Ohio (+2,202), which add up to 15,013. The largest decrease is Illinois, down 4,494.

Wells leave a state inventory when they are plugged or transferred to a new operator, as IOGCC notes, so a net change understates how many wells states added. The abstract of the 2026 release says the update obtained “completely new orphaned wells records” from the states. Each state’s change therefore combines wells plugged, wells newly documented, and any change in how the state or USGS selected records. The two metadata records let some of the largest movements be traced to a documented change of method. Table 4 lists those, and the cases where neither record gives a reason.

Three of the biggest movements coincide with a change of source or definition. New Mexico went from 652 to 3,366 between a file of confirmed orphans and the state’s 15-month inactivity list. Nebraska fell from 479 to 32 between an edition that included shut-in wells and one that counts only the abandoned status. Colorado’s list grew from 409 to 1,302, and the 2022 record shows its source was a 2019 file. The records do not split each of these moves between the change of method and real change on the ground, so none of them measures how many wells were abandoned in a year. They show that the lists were rebuilt.

The drops in Illinois and Wyoming are the opposite case: the records give no reason, and the method text is unchanged. For Illinois the IOGCC figure of 3,946 at the end of 2023 is close to the 2026 value of 3,986 and far from the 2022 value of 8,480, which suggests the state’s own list shrank before 2023. That is an inference from three numbers, and neither report says it.

USGS against IOGCC, state by state

IOGCC’s survey asks each state agency for its documented orphan wells at December 31 of the survey year. USGS builds its database from the same agencies’ lists, but later, and with a location requirement. Table 5 sets the two side by side for every state either compiled. The IOGCC column is Table 2 of its 2024 supplemental report; its rows add to the published total of 141,959.

For the 27 states in both, the database totals 129,661 and IOGCC’s survey 141,948, a net gap of 12,287 wells. The net hides gross differences of 18,741 wells: USGS is higher in ten states by 3,227 in all and lower in seventeen by 15,514. In ten states the two agree within 10 percent (Ohio, Oklahoma, Kentucky, Texas, New York, Louisiana, Missouri, Illinois, New Mexico and Alaska), which includes four of the five largest. The five biggest shortfalls in the USGS count (Pennsylvania -5,978, California -2,393, West Virginia -2,253, Oklahoma -1,703 and Kansas -1,147) sum to 13,474, which is 87% of all the shortfalls.

Pennsylvania is the clearest case. IOGCC records 27,240 and USGS 21,262, a difference of 5,978. The USGS selection was the department’s orphan and abandoned lists in a file dated March 6, 2026, and the 2022 record shows 7,749 wells were removed for missing coordinates in that edition. The two documents do not say what the state included in its 2023 total or why the two lists differ, so the gap can be described but not explained. The same applies to California, where the database total of 2,940 comes from idle-well report appendices dated December 31, 2023 and the survey records 5,333.

Several general reasons are documented, and each can move a state in either direction. The dates differ: the survey is a year-end 2023 snapshot, while 26 of the 28 USGS state files are dated 2025 or 2026. The coverage differs: the 2026 metadata states “Locations without coordinates were removed” and that records with significant location errors were removed too, and the IOGCC report describes no comparable filter. The selection differs, as Table 2 shows. And the question differs: the survey asks for documented orphan wells under each state’s term, while the USGS selection for several states is a list labeled abandoned, inactive or unknown. North Dakota is an example of the last effect: the database counts 562 wells in an “abandoned” status defined as shut in for more than 12 months, and the survey records 80.

Orphaned wells against producing wells

A count of orphans means more beside the size of the industry that produced them. The EIA’s well census, which ended with the December 2025 release, gives producing oil and gas wells for 2024 in 22 of the 28 states (see how many oil wells are in the US). Table 6 divides the two. It is a ratio of two different populations, not a share: an orphaned well is not producing and so is not in the EIA count.

New York leads with 72.4 orphaned wells for every 100 producing, followed by Ohio (63.5), Oklahoma (29.7) and Pennsylvania (25.2). Those four are the only states in the table at or above 20 per 100; Louisiana is next at 17.3. Texas, with 281,164 producing wells, is at 3.2, and twelve of the 22 states are under 5. One reading, which neither source states, is that the high-ratio states are old-field states whose producing wells have thinned out while their orphans accumulated, and that the low-ratio states include the large active fields of Texas and North Dakota. The ratio is consistent with that reading but does not test it, since the EIA counts only wells that produced in the year.

Kentucky does not fit the table because EIA’s Kentucky table is for 2023, with 14,048 producing wells. The state’s 15,638 orphaned wells already exceed that figure, a ratio of 111.3 per 100. EIA states that it repeats Kentucky’s 2023 data for 2024 because the state reports late, so the true 2024 ratio could differ. The other states with an older EIA table are Missouri (table for 2019, 30 wells), Tennessee (table for 2022, 1,675 wells) and Arizona (table for 2021, 12 wells). Illinois and Indiana have no EIA data at all, which leaves 4,932 orphaned wells in two states with no producing-well benchmark in the EIA files.

IOGCC offers a different denominator. Its 29 states reported 1,620,896 wells drilled and not plugged at the end of 2023, a total the report splits into production, injection, monitoring, gas storage and other wells. The 141,959 documented orphan wells are 8.8% of that figure, which the report gives as an overall average of 8.8 percent, with a state range from zero to 83 percent. That denominator covers wells drilled and not plugged whether or not they produce, so it measures orphans against all unplugged wells rather than against active ones.

Who owns the land under the wells

The federal share of the money is small, and in the USGS estimate below federal land holds a minority of the wells: the IIJA gave $250 million of its $4.677 billion to the federal program and $4.275 billion to the state program. The USGS database adds an estimate of surface ownership by matching each well’s coordinates against the Bureau of Land Management’s national map of surface management agencies. The metadata notes that the ownership information is not official: it is a product of spatial operations that do not account for location errors or lease details, and the states did not provide ownership at the well level. With that warning, the federal surface estimate covers 12,369 of the 130,121 wells, 9.5% of the total.

The Forest Service accounts for 9,576 of the 12,369 estimated federal-surface wells, and 9,419 of those are in Ohio, Kentucky and Pennsylvania. In New Mexico the estimate is almost entirely Interior land, 1,297 of 1,305 federal-surface wells. Within Interior’s 2,523 wells the database names the Bureau of Land Management for 1,343, the Bureau of Indian Affairs for 688, the Fish and Wildlife Service for 445, the National Park Service for 32 and the Bureau of Reclamation for 15. The 270 Defense wells include 183 on Army Corps of Engineers land.

Interior’s Federal Orphaned Wells Program is the part of the funding aimed at these sites. The fiscal 2025 report says the federal partners had been funded to plug 1,115 wells and had plugged 231 of them (20.7%) by September 30, 2025, spread across the Bureau of Land Management (93 wells), the Bureau of Safety and Environmental Enforcement (29), the Fish and Wildlife Service (564), the Forest Service (336) and the National Park Service (93). For Tribal land the report says Tribes had identified over 600 wells for plugging, more than 1,000 more were being assessed for eligibility, and 30 had been plugged with Tribal program money.

Plugging pace and the cost arithmetic

The IIJA appropriated $4.677 billion for orphaned wells: $250 million for federal land, $4.275 billion for state and private land, $150 million for Tribal land, and $2 million for IOGCC coordination. By the end of fiscal 2025 Interior had distributed about $1.85 billion of that to federal, state and Tribal recipients. Interior’s report says state grant recipients had plugged 10,257 wells by June 2025, which is 7.9% of the 130,121 in the 2026 database. IOGCC records the acceleration that the grants started: its 29 states plugged 8,732 orphan wells in 2023, 3.1 times the 2,812 of 2022, and 14,580 from 2021 through 2023, 7,239 (50%) with federal funds. The states have plugged at least 96,506 orphan wells since their programs began.

The cost per well rose too. For the 25 states that reported spending from 2021 through 2023, the average was $37,084 a well, within a state range of $3,664 to $249,000. IOGCC’s Figure 7 puts the average at $20,502 in 2018 and $41,759 in 2023, a 2.0-fold increase. The report says depth, condition, location and access drive the spread, and that most states include basic site restoration in the plugging figure. Table 8 turns those averages into rough orders of magnitude. It is arithmetic on state-reported averages for wells that were actually plugged, not a cost estimate for the remaining inventory.

On those inputs the documented inventory is a bill of $4.8 billion to $5.4 billion, above the whole $4.677 billion appropriation, which at the 2023 average buys about 112,000 wells before administrative costs and before any of it goes to the Tribal and federal programs. Plugging at the 2023 pace would run for about 15 years, and the list grew by 12,449 between editions. None of that is a forecast: the state averages run from $3,664 to $249,000, so a state with cheap wells would spend far less than one with deep or damaged wells, and the first wells plugged are not necessarily typical of the rest. What the arithmetic does show is that, at the 2023 state-reported average, the appropriation does not cover even the documented list, before any undocumented well.

Interior also attaches climate and jobs numbers to the program. Its fiscal 2025 report estimates that 5,217 jobs were created from about $479.9 million in funds obligated, and that documented and undocumented orphaned wells together may emit nearly 63 million grams of methane per hour. Plugging the wells funded through June 2025 is estimated to prevent 5.9 billion grams of methane a year. The jobs figure can be set beside the payroll series in oil and gas jobs by year, and the methane estimate is a separate measure from the vented and flared gas volumes in natural gas flaring by state.

Wells that appear on no list

The IOGCC report explains: “The term ‘undocumented well’ refers to a well that is entirely unknown to the regulatory agency or a well of which the agency has some evidence, but which requires further records research or field investigation for verification.” For 2023 the states estimated between 250,000 and 740,000 such orphaned wells, down from 310,000 to 800,000 for 2020. Six states gave no estimate, seven states reported none, and the other 16 gave figures from 2 to more than 100,000. The report calls the estimates “by their nature imprecise.” The USGS 2023 data report goes further and says the true amount including all states is probably higher.

Pennsylvania’s upper bound alone is 76% of the national upper bound, so the national range is mostly a statement about one state’s estimate, and moves a great deal if that estimate is revised. At the low end of each range, six of the seven states put the undocumented wells above the documented count, at 1.2 to 4.7 times it; Kentucky, whose orphan list is already long, estimates only 3,000. The estimates are the states’ own judgments about wells that may predate record keeping, which is why a documented count should not be read as the size of the problem. For the Department of Energy’s Undocumented Orphaned Wells Program, Interior’s fiscal 2024 report says the law allocated $30 million; the program set up a consortium of five national laboratories, CATALOG, that is integrating drones, artificial intelligence and sensing technologies to find such wells. The USGS data report puts the end of the process plainly: once a well is located, it becomes documented.

Picking the right number to cite

The choice depends on the question. Table 10 matches common uses to the count that fits them, with the weakness of each.

The headline will change again. USGS says the national count “is constantly evolving owing to efforts by the states to update their databases, and as new orphaned wells are identified and plugged.” Anyone building on these figures should carry the edition and the date, as Table 3 does, and should compare states only where the Table 2 selection rules are close. The producing side of the same states is in US oil production by state and natural gas production by state, how states tax output, including the reduced rates Texas applies to inactive and orphan wells, is in oil and gas severance tax by state, and the wells that sit between the rig and the producing count are in drilled but uncompleted wells.

Sources and check dates

Data and sources, all checked November 4, 2026: U.S. Geological Survey, United States Documented Orphaned Well Database 2026 (Merrill, Varela and Gianoutsos; ScienceBase item 6aad481a1ba49ba9a487439b; published September 30, 2026; 130,121 wells in 28 states) with its metadata record and the DOWDB API (per-state, type, status and surface-ownership counts); the superseded 2022 edition (Grove and Merrill; 117,672 wells in 27 states; US_orphaned_wells.csv counted by state), whose landing page now points to the 2026 edition; and USGS Data Report 1167 (version 1.1, April 2023). Interstate Oil and Gas Compact Commission, Idle and Orphan Oil and Gas Wells: Supplemental Information on Orphan Well Plugging and Site Restoration, 2024 (revised September 27, 2024; data as of December 31, 2023; Tables 2 and text; the latest edition on the IOGCC publications page). U.S. Department of the Interior, Orphaned Wells Program Office, Annual Report to Congress, FY 2025 (November 2025), the FY 2024 report (November 2024) and the program pages at doi.gov/orphanedwells. 42 U.S.C. 15907, from uscode.house.gov (text current through Public Law 119-136, October 22, 2026). U.S. Energy Information Administration, U.S. Oil and Natural Gas Wells by Production Rate, release of December 8, 2025 (discontinued effective October 15, 2026), Appendix B workbook. Interior’s maps-and-data page still cites “more than 117,000” orphaned wells, the 2022 USGS count. Texas Railroad Commission, Orphan Wells with Delinquent P-5 Greater Than 12 Months (definition quoted in the text). Shares, differences, ratios and cost arithmetic are this page’s calculations. Idaho and Virginia are in the IOGCC survey but not in the USGS database, Arizona is in the USGS database but not in the IOGCC table, and Illinois and Indiana are not in the EIA workbook.