OPERATORS · RRC 780219 · P-5 STATUS Y

Sierra Oil Co

Fort Worth, TX

Sierra Oil CO has filed no drilling permits in the past 12 months; its most recent permit was issued March 1, 1994.

The RRC wellbore file lists 14 wells under its operatorship.

45 drilling permits have been issued to this operator number since 1987; its P-5 organization report was last filed June 4, 2026.

0: permits, last 12 months
—: vs prior 12 months (0)
0: counties, 12 months
0: producing wells, of 14 of record
17: leases it reports
—: horizontal, 12 months

WINDOWS ON THE RRC ISSUE DATE · COMPUTED OCT 29, 2026

From permit to spud

FROM THE DATES ON ITS W-1 PERMITS · ALL TIME

A permit is a plan, not a well. These figures count only permits old enough to have spudded, six months and more, and read the spud, cancel, and expiry dates the RRC records on each one.

11%: spud rate · 5 of 45 mature permits
9: median days permit to spud · middle half 5–12
0: spuds, last 180 days
0%: cancelled · 0 permits
40: expired undrilled
6: permits a year over 7 active years

Where

Counties by permits in the last 12 months, with all-time permits and current wells of record there.

County	12 mo	All time	Wells	Last
Eastland county →	—	45	14	Mar 1, 1994

All 45 permits, searchable → · Leases it reports → · On the map →

Formations in its completed wells

Tops reported on completion filings for wells it operates. RRC wellbore file. About tops →

Formation	Wells	Permitted last 3 yrs
Marble Falls	18	0
Duffer	13	0
Barnett	8	0
Mississippian	6	0
Caddo	1	0
Strawn	1	0
Big Saline	1	0

Production by month

PDQ LEASE REPORTS · REPORTED THROUGH APR 2026

Barrels on leases where this operator filed the production report. Lease-level by design; the latest months are revised upward as late reports arrive. How production is reported →

0: bbl oil, last 12 reported months
—: vs the 12 months before
0: mcf gas incl. casinghead, last 12
9.4K: bbl oil since reporting began

No lease production reported under this operator number in the last three years.

Beyond the permit record

RRC wellbore file

Wells of record

14: on the schedule
0: producing
0: shut in
0: injection
0: temp. abandoned
13: plugged

How it got them

13: permitted itself
1: acquired from others
10: permitted, now run by others

Acquired means the well's permit names a different operator than the schedule does today. Transfers and operator numbers →

RRC UIC permits · H-10 reported volumes

Disposal and injection

0: active UIC permits of 1
0: permitted bbl/day, active
0: bbl injected, last 12 reported months
Jun 2025: reported through

By county

Eastland

0 active

0 bbl/d

Permitted volume is a ceiling, not throughput. How to read it →

Permit types

Last 12 months against the prior 12, and all time. A type opens the permit history filtered to it. What the types mean →

Type	12 mo	Prior 12	All time
Drill	0	0	38
Recompletion	0	0	3
Other	0	0	2
Reenter	0	0	1
Field transfer	0	0	1

Fields

RRC regulatory fields with the most wells of record under this operator. The field opens its page; the count opens this operator's wells in it.

Field	Wells	Producing
Crawford (Marble Falls)21587600	6	0
Eastland County Regular27358001	2	0
Missy a (Strawn)62161700	2	0
Burt & Cody (Bend Congl.)13914300	1	0
Sovereign Genesis (Miss)84844250	1	0
Sierra (Ranger Lime)83490400	1	0
Carbon (Marble Falls)15575380	1	0

P-5 organization report

As registered with the RRC. About the P-5 →

Registration: Status code Y; Last filed Jun 4, 2026; Gas operator

Address: 2739 N Main St; Fort Worth, TX 76106

Officers and agents: Maddox, Susan J. · Texas Resident Agent; Maddox, Keith · Chairman/President/Secretary; Maddox, Susan J. · Vice President/Treasurer

Latest permits

NEWEST FIRST BY ISSUE DATE · FILED OR ON WELLS IT NOW OPERATES

Permit	Seen	Issued	Operator	County	Lease / well	Depth	API
421644	Mar 1, 1994	Mar 1, 1994	Sierra Oil Company	Eastland	Crawford, A.D. #2A	3,430	13337636
411178	Nov 8, 1993	Nov 8, 1993	Sierra Oil Company	Eastland	Crawford, A.D. #4	4,000	13337643
408973	Feb 12, 1993	Feb 12, 1993	Sierra Oil Company	Eastland	Crawford, A.D. #2A	4,000	13337636
404222	Oct 2, 1992	Oct 2, 1992	Sierra Oil Company	Eastland	Crawford, A.D. #3	2,000	13337620
404222	Oct 2, 1992	Oct 2, 1992	Sierra Oil Company	Eastland	Crawford, A.D. #3	2,000	13337620
389870	Jul 17, 1991	Jul 17, 1991	Mitchell Energy Corporation	Eastland	Pilgrim #1	3,600	13337251
385730	Mar 19, 1991	Mar 19, 1991	Sierra Oil Company	Eastland	Love, Ronnie N. #1	2,500	13337323
374094	Jun 4, 1990	Jun 4, 1990	Sierra Oil Company	Eastland	Treasure JO #1	3,850	13337458
358432	Apr 21, 1989	Apr 21, 1989	Sierra Oil Company	Eastland	Crawford, Elizabeth #1	3,900	13337347
358291	Apr 17, 1989	Apr 17, 1989	Sierra Oil Company	Eastland	Love, Barbara Ann #1	3,900	13337363
354099	Dec 8, 1988	Dec 8, 1988	Sierra Oil Company	Eastland	Veale, Loresta #1	3,900	13337343
354099	Dec 8, 1988	Dec 8, 1988	Sierra Oil Company	Eastland	Veale, Loresta #1	3,900	13337343
351479	Sep 22, 1988	Sep 22, 1988	Sierra Oil Company	Eastland	Love #1	3,900	13337323
351478	Sep 22, 1988	Sep 22, 1988	Sierra Oil Company	Eastland	Enserch #3	3,900	13337322
349372	Jul 25, 1988	Jul 25, 1988	Sierra Oil Company	Eastland	Jones Heirs #1	3,900	13337306

Full permit history →

About this data

Registration from the RRC P-5 organization report, refreshed weekly. Permits from the OGA049M master and daily daf420 files; wells of record from the EWA wellbore schedule; production from PDQ lease reports at the last vintage; disposal from UIC permits and H-10 reports. Summary figures are rebuilt nightly.

Developers: this page as JSON is GET /v1/data/operators/tx/780219, documented in the API reference.