This map shows oil and gas well density across every US county, drawn from the FracTracker Alliance national well database as of March 2024. Each county is shaded by its total recorded well count — pale yellow for counties with a handful of wells, deep red for the most drilled counties in the country. Across 37 states, the database records approximately 4.92 million individual wells in 2,146 counties. The remaining 1,087 US counties have no wells in the dataset, either because they lack suitable geology or because they fall outside the 37 states covered.
Interactive Map: US Oil and Gas Wells by County
Use the state filter above the map to zoom to a specific state. Click any shaded county to see its total well count, producing and plugged well breakdown, wells per square mile, and a link to the full state-level interactive map where you can explore individual well points.
Explore oil & gas wells by state
How to Use This Map
Reading the Color Scale
The five color classes use quantile breaks — each class contains roughly the same number of counties with wells, so the color reflects relative concentration rather than absolute volume. A county in the darkest class sits in the top 20% of all drilled counties nationally, not just within its own state. The exact class ranges (1–48, 49–232, 233–1,368, 1,369–4,390, 4,391+) appear in the legend at the lower right of the map.
Filter by State
The dropdown above the map jumps to any of the 37 oil-producing states and filters the choropleth so you can compare counties within a single state. To return to the national view, select “All States.” For a state-level breakdown with individual well points and status filtering, click the link in any county popup to go to the full state interactive map.
County Popups
Clicking any county shows: total well count, producing well count, plugged well count, other-status count, and a wells-per-square-mile density figure calculated from the county’s land area. The “other status” category includes orphaned wells, wells under regulatory review, injection wells, and records with incomplete status filings.
US Oil and Gas Wells by State: Full Rankings
Texas accounts for more than one in three oil and gas wells in the entire country. Kansas ranks second nationally — a result that surprises most people, who tend to associate high well counts with Texas, Oklahoma, or Pennsylvania. The state’s 499,732 wells reflect over a century of conventional oil and gas development across the mid-continent sedimentary basin. Together, the top three states (Texas, Kansas, Oklahoma) hold 53.6% of all recorded US wells.
| Rank | State | Total Wells | Producing | Plugged | Share of US Total |
|---|---|---|---|---|---|
| 1 | Texas | 1,703,194 | 694,157 | 515,901 | 34.6% |
| 2 | Kansas | 499,732 | 136,097 | 157,444 | 10.2% |
| 3 | Oklahoma | 436,988 | 125,111 | 235,226 | 8.9% |
| 4 | Ohio | 240,052 | 96,191 | 70,531 | 4.9% |
| 5 | California | 238,997 | 39,701 | 128,989 | 4.9% |
| 6 | Louisiana | 224,547 | 47,499 | 81,470 | 4.6% |
| 7 | Pennsylvania | 219,479 | 105,372 | 53,720 | 4.5% |
| 8 | Illinois | 197,348 | 48,506 | 103,882 | 4.0% |
| 9 | Kentucky | 158,482 | 68,919 | — | 3.2% |
| 10 | Wyoming | 141,259 | 66,796 | — | 2.9% |
| 11 | New Mexico | 132,796 | 63,802 | 48,234 | 2.7% |
| 12 | Colorado | 122,908 | 44,592 | 50,776 | 2.5% |
| 13 | West Virginia | 113,159 | 34,222 | 24,802 | 2.3% |
| 14 | Michigan | 95,151 | 29,114 | 1,433 | 1.9% |
| 15 | Indiana | 75,555 | 8,198 | 20,963 | 1.5% |
| 16 | New York | 45,476 | 14,129 | 19,787 | 0.9% |
| 17 | Montana | 44,186 | 22,616 | — | 0.9% |
| 18 | North Dakota | 41,050 | 30,223 | — | 0.8% |
| 19 | Utah | 38,797 | 14,327 | 9,533 | 0.8% |
| 20 | Arkansas | 33,606 | 16,125 | — | 0.7% |
| 21 | Mississippi | 25,453 | 4,788 | 18,454 | 0.5% |
| 22 | Nebraska | 22,260 | 2,083 | 5,413 | 0.5% |
| 23 | Alabama | 18,456 | 6,372 | 4,559 | 0.4% |
| 24 | Tennessee | 16,412 | 11,332 | — | 0.3% |
| 25 | Virginia | 12,755 | 8,398 | 225 | 0.3% |
| 26 | Missouri | 10,224 | 645 | 4,283 | 0.2% |
| 27 | Alaska | 7,238 | 2,743 | 2,662 | 0.1% |
| 28 | South Dakota | 2,044 | 422 | 1,427 | <0.1% |
| 29 | Florida | 1,435 | 93 | 970 | <0.1% |
| 30 | Arizona | 1,252 | 68 | 161 | <0.1% |
| 31 | Washington | 823 | 683 | 112 | <0.1% |
| 32 | Nevada | 781 | 70 | 534 | <0.1% |
| 33 | Maryland | 219 | — | — | <0.1% |
| 34 | Idaho | 212 | 16 | 38 | <0.1% |
| 35 | Oregon | 89 | 28 | — | <0.1% |
| 36 | Minnesota | 1 | — | — | <0.1% |
| 37 | Iowa | 2 | — | — | <0.1% |
Top 20 Counties by Total Well Count
Kern County, California holds the record by a wide margin, with 156,441 wells — nearly three times the second-ranked county. The San Joaquin Valley oil fields beneath Kern County have been drilled continuously since the 1860s and remain commercially active today, though the county’s 72,259 plugged wells reflect both the age of the field and California’s active legacy-well decommissioning programs. Texas occupies nine of the top 20 spots, with multiple Permian Basin counties concentrated in the upper tier.
| Rank | County | State | Total Wells | Producing | Plugged |
|---|---|---|---|---|---|
| 1 | Kern | California | 156,441 | 30,728 | 72,259 |
| 2 | Wichita | Texas | 50,468 | 17,252 | 14,878 |
| 3 | Weld | Colorado | 44,830 | 15,092 | 17,700 |
| 4 | Lea | New Mexico | 44,608 | 19,782 | 17,334 |
| 5 | Archer | Texas | 41,773 | 8,224 | 12,991 |
| 6 | Campbell | Wyoming | 38,962 | 19,170 | — |
| 7 | Andrews | Texas | 38,112 | 19,834 | 10,438 |
| 8 | Eddy | New Mexico | 37,716 | 18,931 | 11,812 |
| 9 | McKean | Pennsylvania | 37,240 | 10,115 | 19,398 |
| 10 | Caddo | Louisiana | 36,353 | 13,401 | 13,076 |
| 11 | Ector | Texas | 33,452 | 15,641 | 9,766 |
| 12 | Young | Texas | 32,659 | 7,135 | 9,503 |
| 13 | Creek | Oklahoma | 32,200 | 6,924 | 15,358 |
| 14 | Pecos | Texas | 29,852 | 16,519 | 6,661 |
| 15 | Shackelford | Texas | 24,910 | 5,775 | 8,145 |
| 16 | Los Angeles | California | 24,697 | 2,596 | 17,400 |
| 17 | Okmulgee | Oklahoma | 24,097 | 3,801 | 11,640 |
| 18 | Montgomery | Kansas | 23,501 | 7,213 | 8,600 |
| 19 | Howard | Texas | 23,405 | 12,081 | 5,781 |
| 20 | Midland | Texas | 22,985 | 14,294 | 6,697 |
Well Concentration: Counties with the Most Wells per Square Mile
Total well count favors large counties. A different picture emerges when you normalize by land area. Wichita County, Texas — 627 square miles in North Texas — holds 50,468 wells, giving it a density of 80 wells per square mile, the highest of any major oil-producing county in the country. Gregg County in East Texas (home of the giant East Texas Oil Field, discovered in 1930) reaches 63 wells per square mile in just 273 square miles. Crawford County, Illinois, at the heart of the Illinois Basin, packs 48 wells into each square mile of its modest 444-square-mile footprint.
Kern County’s 156,441 total wells translate to only 18 wells per square mile — the county is 8,163 square miles, roughly the size of New Jersey. Large Permian Basin counties like Pecos (4,765 sq mi) and San Juan, New Mexico (5,514 sq mi) similarly rank lower on density despite high total counts. The national interactive point map lets you zoom into any of these counties to see how individual wells cluster spatially within the county boundary.
Understanding the Three US Drilling Heartlands
The county choropleth reveals three distinct clusters of high well density, each with a different geological history and economic profile.
Permian Basin (West Texas and Southeast New Mexico)
The Permian Basin is the most productive oil region in the United States and one of the most productive in the world. Counties including Andrews, Ector, Lea, Eddy, Midland, Pecos, and Howard all appear in the top 20 by total well count, and most have strong producing-well ratios reflecting active development. Lea County, NM has 19,782 producing wells out of 44,608 total (44%), and Andrews County, TX has 19,834 producing out of 38,112 (52%) — among the highest active-production ratios in the country. Explore the full Permian Basin context on the Texas oil and gas wells map and the New Mexico oil and gas wells map.
Mid-Continent (Kansas, Oklahoma, North Texas)
Kansas and Oklahoma together account for 19.1% of all US wells. This region reflects over a century of conventional oil and gas development. Kansas has more total wells than California, Louisiana, or Pennsylvania combined — a figure that surprises most people unfamiliar with the Kansas mid-continent play. Oklahoma’s 436,988 wells show a different pattern: 53.8% are plugged, reflecting an older well stock with many legacy fields exhausted or decommissioned. North Dakota’s Williston Basin (Bakken Shale) stands out within this broader region: 73.6% of its 41,050 wells are actively producing, the highest rate of any state with more than 10,000 wells, reflecting the relatively young age of Bakken development (post-2008). To see the infrastructure that moves this production to market, see our national natural gas pipelines map.
Appalachian Basin (Pennsylvania, Ohio, West Virginia, New York)
The Appalachian Basin has the oldest oil and gas history in the country. Pennsylvania’s Drake Well (1859) launched the US petroleum industry, and the region has been drilled continuously for 165 years. Pennsylvania’s 219,479 wells include both Marcellus Shale horizontals (post-2005, mostly producing) and thousands of legacy vertical wells drilled in the late 19th and early 20th centuries. McKean County, PA (37,240 wells, 37th in the country) was the center of Pennsylvania’s earliest oil rush. Ohio’s 240,052 wells rank fourth nationally — a figure rarely cited in discussions of US oil production but reflecting dense conventional drilling across eastern Ohio’s Utica and Clinton formations. West Virginia’s 113,159 wells are dominated by natural gas production, with much of the output feeding East Coast markets via pipelines visible on our national gas pipeline map. Pennsylvania shows one of the highest active-well ratios of any major producing state at 48% — driven by Marcellus Shale wells that came online in the past 15 years.
Well Status: What the Data Tells Us About Producing, Plugged, and Abandoned Wells
Each well in the FracTracker dataset carries a reported status. Three categories dominate the county-level summary data on this map.
Producing wells are actively extracting oil or gas at the time of the dataset snapshot (March 2024). Nationally, the FracTracker data indicates approximately 35% of recorded wells are in active production status. States with the highest production ratios tend to be either very active (North Dakota at 73.6%, driven by recent Bakken development) or very small (Washington at 83%, with only 823 total wells). Among major producing states, Pennsylvania leads at 48% and Texas sits at 40.8%.
Plugged wells have been formally decommissioned and sealed per regulatory requirements. California’s Kern County has 72,259 plugged wells — 46% of its total — reflecting both the age of the San Joaquin Valley fields and California’s relatively rigorous plugging enforcement. Mississippi has the highest state-level plugging rate: 72.5% of its 25,453 wells are plugged, indicating heavily exhausted conventional fields. Oklahoma (53.8% plugged) and California (54.0% plugged) show similar patterns. Plugged wells, when properly sealed, should not pose ongoing environmental risk, though well integrity degrades over time.
Other status encompasses orphaned wells (those with no identified responsible owner, legally required to be plugged but unfunded), injection wells used for saltwater disposal or enhanced recovery, and wells with incomplete or unreported status. The US EPA estimates there are over 2 million documented abandoned or orphaned wells nationwide, and potentially millions more undocumented. Several states — Wyoming, North Dakota, Montana, Kentucky, Tennessee — show zero or near-zero plugged well counts in this dataset, likely reflecting data reporting differences rather than actual absence of plugged wells. The broader infrastructure picture, including how producing wells connect to downstream processing and transport, is visible on our Gulf of Mexico oil and gas infrastructure map and the US power plants map.
Data Sources and Limitations
Well counts on this map come from the FracTracker Alliance National Wells (NatWells) dataset, with a snapshot date of March 1, 2024. The FracTracker dataset aggregates well records from state oil and gas regulatory agencies across 37 states. County polygons are US Census Bureau TIGER/Line county boundaries, spatially joined to the well point data. The total record count across the 37 covered states is approximately 4.92 million wells.
Thirteen states are not represented in the FracTracker dataset, primarily because they have no meaningful commercial oil and gas production history: Connecticut, Delaware, Georgia, Hawaii, Maine, Massachusetts, New Hampshire, New Jersey, North Carolina, Rhode Island, South Carolina, Vermont, and Wisconsin. These states appear as grey counties on this map.
Well status classifications (producing, plugged, other) derive from state regulatory filings. Reporting lags, classification differences between states, and incomplete historical records mean that status figures should be treated as approximate. Several states report zero plugged wells in this dataset, which is inconsistent with known regulatory activity and almost certainly reflects data gaps rather than ground truth. The dataset covers onshore conventional and unconventional wells and does not include offshore wells, Class II injection wells (saltwater disposal), or geothermal wells.
Frequently Asked Questions
Why does Kansas have more oil and gas wells than Oklahoma or California?
Kansas has been continuously producing oil since the early 1900s from the mid-continent sedimentary basin. Unlike Oklahoma, which has a similar geological setting, Kansas has a higher proportion of small, widely-distributed conventional wells drilled over a longer period. The state’s 105 counties with well data average over 4,700 wells each. Oklahoma’s slightly lower total reflects a different mix of field sizes, not less drilling activity overall.
What is the difference between this county map and the US oil and gas wells point map?
The US oil and gas wells map renders each of the 4.9 million wells as an individual point, color-coded by status, with a nearest-well finder and well-type filters. This county choropleth aggregates those points to show geographic patterns at a national scale. Use this map to identify where drilling is most concentrated across the country; use the point map to explore specific locations, well types, and individual well details.
Why do some counties appear grey?
Grey counties have no wells in the FracTracker dataset, either because the county has no oil or gas geology, because the state is not covered by the dataset, or because any historical drilling was too limited to appear in the national compilation. The 13 states with no coverage appear entirely grey.
Which county has the most wells per square mile?
Wichita County, Texas leads the counties covered in this dataset with approximately 80 wells per square mile. Other high-density counties include Gregg County, Texas (63 wells/sq mi, heart of the East Texas Oil Field) and Crawford County, Illinois (48 wells/sq mi, Illinois Basin). Note that high total-count counties like Kern County, California score lower on density (18 wells/sq mi) because they cover much larger geographic areas.
What does the plugged well count tell us?
High plugged-well counts generally indicate older, more exhausted fields. Mississippi (72.5% plugged), Nevada (68.4%), and South Dakota (69.8%) have the highest state-level plugging rates — all states with long oil production histories and little recent activity. A high plugging rate is not necessarily negative; it can indicate active regulatory compliance. The concern is unplugged orphaned wells, which may not appear in state records at all.
How current is the data?
The FracTracker NatWells dataset used here has a snapshot date of March 1, 2024. Well counts and status classifications will shift over time as new wells are drilled and existing wells are plugged or change status. For the latest well-level data with search and filtering by status and type, see the interactive US oil and gas wells point map.
