San Marcos Exploration
Operator of record for 3 catalogued wells across 1 state. Every well below links to its full registry page.
At a glance
San Marcos Exploration is the operator of record for 3 catalogued U.S. oil & gas wells in 1 state. None is listed as active, 3 (100%) are plugged & abandoned. Its largest concentration is in Illinois, with 3 wells (100% of its portfolio).
Wells operated
3
Active
0
Plugged
3
Orphaned
0
Portfolio by state
| State | Wells |
|---|---|
| Illinois | 3 |
Well mix
- Oil wells
- 2
- Gas wells
- 0
- Shut-in
- 0
- Active share
- 0%
Is this your company?
Claim San Marcos Exploration to keep this portfolio accurate — verified operators can correct well statuses and add plugging documentation.
Claim your operator profileWhere does San Marcos Exploration operate?
San Marcos Exploration's catalogued wells are spread across 1 state: Illinois (3). Its 3 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 San Marcos Exploration’s wells are active, plugged or orphaned?
0% of San Marcos Exploration's catalogued wells are active, 29 percentage points below the national share of 29%. 100% are plugged & abandoned, against 47% nationally. None of the wells filed under this name is flagged as orphaned.
What kinds of wells does San Marcos Exploration operate?
By product class, 2 (67%) 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 McComas, Olen 1 in Jasper, IL at 2,656 ft.
Notable wells operated by San Marcos Exploration
| Well | API # / state ID | Status | Type | Location | Operator | Depth |
|---|---|---|---|---|---|---|
| McComas, Olen 1 | 12-079-03079 | Plugged & abandoned | Oil | Jasper, IL | San Marcos Exploration Company | 2,656 ft |
| Cowger, A. B. 1 | 12-079-03008 | Plugged & abandoned | Other type | Jasper, IL | San Marcos Exploration Company | 2,638 ft |
| Cowger 1-A | 12-079-03078 | Plugged & abandoned | Oil | Jasper, IL | San Marcos Exploration Company | 2,610 ft |
Deepest first where depth is published. See all 3 wells →
Frequently asked questions
How many wells does San Marcos Exploration operate?
San Marcos Exploration is the operator of record for 3 catalogued oil & gas wells, with the largest concentration in Illinois (3). Only wells in states WellCensus has ingested are counted.
How many of San Marcos Exploration's wells are still active?
0 of San Marcos Exploration's catalogued wells are active; 3 are plugged & abandoned.
In which states does San Marcos Exploration operate wells?
San Marcos Exploration is the operator of record for wells in Illinois (3).
Does San Marcos Exploration operate mostly oil or gas wells?
2 of San Marcos Exploration's catalogued wells are oil wells and 0 are gas wells; the rest are injection, service or unclassified wells.
What is San Marcos Exploration's deepest well?
Among wells with a published depth, McComas, Olen 1 in Jasper, IL is the deepest at 2,656 ft.
Where San Marcos Exploration'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, “San Marcos Exploration — well portfolio”, https://wellcensus.com/operators/san-marcos-exploration-102179 (data as of October 10, 2026).
Dataset updated . Operator portfolios are resolved from raw state registry filings (exact-normalized names; subsidiaries stay separate).