OPERATORS · RRC 780213 · P-5 STATUS Y

Sierra Expl Co

San Antonio, TX

Sierra Expl CO has filed no drilling permits in the past 12 months; its most recent permit was issued November 3, 2005.

The RRC wellbore file lists 14 wells under its operatorship.

68 drilling permits have been issued to this operator number since 1978; its P-5 organization report was last filed July 3, 2008.

0: permits, last 12 months
—: vs prior 12 months (0)
0: counties, 12 months
0: producing wells, of 14 of record
3: 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.

43%: spud rate · 29 of 68 mature permits
14: median days permit to spud · middle half 10–46
0: spuds, last 180 days
0%: cancelled · 0 permits
39: expired undrilled
2: permits a year over 28 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
Jack county →	—	18	12	May 16, 1983
Throckmorton county →	—	12	1	Jul 7, 1988
Live Oak county →	—	11	0	Nov 3, 2005
Young county →	—	8	0	Jun 17, 1988
Concho county →	—	7	1	Aug 31, 1984
Archer county →	—	3	0	Jul 29, 1985
Atascosa county →	—	3	0	Mar 18, 1987
Frio county →	—	2	0	Nov 7, 1989
Baylor county →	—	1	0	Dec 12, 1985
Jim Wells county →	—	1	0	Mar 8, 1979
San Patricio county →	—	1	0	Oct 6, 1978
Shackelford county →	—	1	0	Feb 22, 1983

All 68 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
Caddo	5	0
Marble Falls	4	0
Mississippian	3	0
Palo Pinto	2	0
Bryson	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
50.7K: 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
12: plugged

How it got them

7: permitted itself
4: acquired from others
28: 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

Jack

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	64
Recompletion	0	0	3
Other	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
Ambra (Strawn)2299500	4	0
Jack County Regular (Gas)45274025	3	0
K L M (Caddo B)47872500	2	0
Hull (Caddo A)43393500	1	0
Jack County Regular45274001	1	0
Frog Pond Creek (Cook Sand)33085500	1	0
Lynn Creek (Caddo)56018500	1	0
Throckmorton County Regular89812001	1	0

P-5 organization report

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

Registration: Status code Y; Last filed Jul 3, 2008

Address: 900 NE Loop 410 Ste 408; San Antonio, TX 78209

Officers and agents: Mount, Don L. · President; Colella, Sara Mount · Vice President/Treasurer; Laney, Betty · Secretary

Latest permits

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

Permit	Seen	Issued	Operator	County	Lease / well	Depth	API
608906	Nov 3, 2005	Nov 3, 2005	Sierra Exploration Company	Live Oak	Cartwright -A- #A 6	2,400	29734653
553018	Nov 1, 2004	Nov 1, 2004	Sierra Exploration Company	Live Oak	Cartwright #A 5	2,400	29734588
553017	Nov 1, 2004	Nov 1, 2004	Sierra Exploration Co.	Live Oak	Cartwright #A 4	2,400	29734589
524782	Oct 28, 2002	Oct 28, 2002	Sierra Exploration Co.	Live Oak	Cartwright #A 3	2,200	29734482
502505	Nov 30, 2000	Nov 30, 2000	Sierra Exploration Co.	Live Oak	Cartwright #A 2	4,700	29734410
502505	Nov 30, 2000	Nov 30, 2000	Sierra Exploration Co.	Live Oak	Cartwright #A 2	4,700	29734410
490854	Jan 7, 2000	Jan 7, 2000	Sierra Exploration Co.	Live Oak	Cartwright, C. L. & H. #A 1	4,750	29734378
472009	Jan 15, 1998	Jan 15, 1998	Sierra Exploration Co.	Live Oak	Cartwright, C. L. & H. #1	4,750	29734308
365955	Nov 7, 1989	Nov 7, 1989	Sierra Exploration Co.	Frio	Williams, Blake Jr. #1	5,500	16332590
348572	Jul 7, 1988	Jul 7, 1988	Sierra Exploration Co.	Throckmorton	Thacker #1	4,800	44734892
348572	Jul 7, 1988	Jul 7, 1988	Sierra Exploration Co.	Throckmorton	Thacker #1	4,800	44734892
347844	Jun 17, 1988	Jun 17, 1988	Sierra Exploration Co.	Young	Bryson, H. #1	4,652	50331872
327919	Mar 18, 1987	Mar 18, 1987	Sierra Exploration Co.	Atascosa	Whitfield #3	1,800	01333812
325836	Jan 26, 1987	Jan 26, 1987	Sierra Exploration Co.	Atascosa	Whitfield #2	1,800	01333803
324532	Dec 18, 1986	Dec 18, 1986	Sierra Exploration Co.	Atascosa	Whitfield #1	3,200	01333797

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/780213, documented in the API reference.