Mefford
Operator of record for 8 catalogued wells across 1 state. Every well below links to its full registry page.
At a glance
Mefford is the operator of record for 8 catalogued U.S. oil & gas wells in 1 state. None is listed as active, 6 (75%) are plugged & abandoned. Its largest concentration is in Illinois, with 8 wells (100% of its portfolio).
Wells operated
8
Active
0
Plugged
6
Orphaned
0
Portfolio by state
| State | Wells |
|---|---|
| Illinois | 8 |
Well mix
- Oil wells
- 6
- Gas wells
- 0
- Shut-in
- 0
- Active share
- 0%
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Claim your operator profileWhere does Mefford operate?
Mefford's catalogued wells are spread across 1 state: Illinois (8). Its 8 Illinois wells are 0.0% of the 174,478 catalogued in that state — its largest share of any state. Counts cover only states whose registries WellCensus has ingested with operator names; wells in Nebraska and Texas (location indexes) and in states without a registry ingest are not yet attributed to any operator.
How many of Mefford’s wells are active, plugged or orphaned?
0% of Mefford's catalogued wells are active, 29 percentage points below the national share of 29%. 75% are plugged & abandoned, against 47% nationally. None of the wells filed under this name is flagged as orphaned.
What kinds of wells does Mefford operate?
By product class, 6 (75%) are oil wells and 0 (0%) gas wells; nationally the shares are 43% and 17%. The deepest of its wells with a published depth is Siler, N. W. 6 in Crawford, IL at 1,081 ft.
Notable wells operated by Mefford
| Well | API # / state ID | Status | Type | Location | Operator | Depth |
|---|---|---|---|---|---|---|
| Siler, N. W. 6 | 12-033-09662 | Plugged & abandoned | Oil | Crawford, IL | Mefford | 1,081 ft |
| Siler, N. 2 | 12-033-08061 | Plugged & abandoned | Oil | Crawford, IL | Mefford | 973 ft |
| Siler, M. W. 1 | 12-033-12883 | Other status | Other type | Crawford, IL | Mefford | 962 ft |
| Siler, N. S. 3 | 12-033-07285 | Plugged & abandoned | Oil | Crawford, IL | Mefford | 952 ft |
| Siler, N. J. 4 | 12-033-07290 | Plugged & abandoned | Oil | Crawford, IL | Mefford | 950 ft |
| Siler, N. W. 8 | 12-033-09433 | Plugged & abandoned | Oil | Crawford, IL | Mefford | 947 ft |
| Siler 7 | 12-033-08836 | Plugged & abandoned | Oil | Crawford, IL | Mefford | 941 ft |
| Siler, N.W. 5 | 12-033-12884 | Other status | Other type | Crawford, IL | Mefford | 917 ft |
Deepest first where depth is published. See all 8 wells →
Frequently asked questions
How many wells does Mefford operate?
Mefford is the operator of record for 8 catalogued oil & gas wells, with the largest concentration in Illinois (8). Only wells in states WellCensus has ingested are counted.
How many of Mefford's wells are still active?
0 of Mefford's catalogued wells are active; 6 are plugged & abandoned.
In which states does Mefford operate wells?
Mefford is the operator of record for wells in Illinois (8).
Does Mefford operate mostly oil or gas wells?
6 of Mefford's catalogued wells are oil wells and 0 are gas wells; the rest are injection, service or unclassified wells.
What is Mefford's deepest well?
Among wells with a published depth, Siler, N. W. 6 in Crawford, IL is the deepest at 1,081 ft.
Where Mefford's wells are
About this data
Source: State oil & gas regulator registries (operator of record as filed, exact-normalized across states) plus the USGS United States Documented Orphaned Well Database (2026), as published October 10, 2026 — WellCensus refreshes it monthly. See the methodology for how records are matched, cleaned and scored.
Cite as: WellCensus, “Mefford — well portfolio”, https://wellcensus.com/operators/mefford-96054 (data as of October 10, 2026).
Dataset updated . Operator portfolios are resolved from raw state registry filings (exact-normalized names; subsidiaries stay separate).