Sierra Exploration
Operator of record for 2 catalogued wells across 2 states. Every well below links to its full registry page.
Filed as: SIERRA EXPLORATION CO · Sierra Exploration Corp.
At a glance
Sierra Exploration is the operator of record for 2 catalogued U.S. oil & gas wells in 2 states. None is listed as active, 2 (100%) are plugged & abandoned. Its largest concentration is in Colorado, with 1 wells (50% of its portfolio).
Wells operated
2
Active
0
Plugged
2
Orphaned
0
Portfolio by state
| State | Wells |
|---|---|
| Colorado | 1 |
| Illinois | 1 |
Well mix
- Oil wells
- 0
- Gas wells
- 0
- Shut-in
- 0
- Active share
- 0%
Is this your company?
Claim Sierra Exploration to keep this portfolio accurate — verified operators can correct well statuses and add plugging documentation.
Claim your operator profileWhere does Sierra Exploration operate?
Sierra Exploration's catalogued wells are spread across 2 states: Colorado (1) and Illinois (1). Its 1 Colorado wells are 0.0% of the 124,327 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 Sierra Exploration’s wells are active, plugged or orphaned?
0% of Sierra 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 Sierra Exploration operate?
By product class, 0 (0%) 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 Yosanovich 1-A in Franklin, IL at 2,705 ft. The wells listed below sit in Franklin (IL) and Archuleta (CO). State filings spell the name 2 ways; WellCensus merges exact-normalized spellings only, so subsidiaries and affiliates keep their own pages.
Notable wells operated by Sierra Exploration
| Well | API # / state ID | Status | Type | Location | Operator | Depth |
|---|---|---|---|---|---|---|
| Yosanovich 1-A | 12-055-22714 | Plugged & abandoned | Other type | Franklin, IL | Sierra Exploration Corp. | 2,705 ft |
| 1 (Owp) Schick, Mizar | 05-007-06069 | Plugged & abandoned | Other type | Archuleta, CO | Sierra Exploration Co | 2,320 ft |
Deepest first where depth is published. See all 2 wells →
Frequently asked questions
How many wells does Sierra Exploration operate?
Sierra Exploration is the operator of record for 2 catalogued oil & gas wells, with the largest concentration in Colorado (1). Only wells in states WellCensus has ingested are counted.
How many of Sierra Exploration's wells are still active?
0 of Sierra Exploration's catalogued wells are active; 2 are plugged & abandoned.
In which states does Sierra Exploration operate wells?
Sierra Exploration is the operator of record for wells in Colorado (1) and Illinois (1).
Does Sierra Exploration operate mostly oil or gas wells?
0 of Sierra Exploration's catalogued wells are oil wells and 0 are gas wells; the rest are injection, service or unclassified wells.
What is Sierra Exploration's deepest well?
Among wells with a published depth, Yosanovich 1-A in Franklin, IL is the deepest at 2,705 ft.
Where Sierra 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, “Sierra Exploration — well portfolio”, https://wellcensus.com/operators/sierra-exploration-19550 (data as of October 10, 2026).
Dataset updated . Operator portfolios are resolved from raw state registry filings (exact-normalized names; subsidiaries stay separate).