Miocene (undifferentiated) Formation

Operator-reported tops from 7,170 wells across 50 counties, median tops running 560–7,010 ft by county.

Top depth: 400 ft 5,292 ft

886 wells shown (sampled from 7,170)

Depth by County

County	Wells	Median Top	Typical Range	CSV
Wharton	617	2,682 ft	950–5,350	↓
Refugio	524	2,316 ft	1,504–3,050	↓
Hardin	411	1,322 ft	1–3,057	↓
Victoria	404	1,510 ft	1–2,820	↓
Fort Bend	382	3,050 ft	1,150–4,387	↓
Brazoria	372	3,243 ft	1,300–6,365	↓
Jackson	321	1,800 ft	1–4,500	↓
Liberty	309	1,915 ft	710–4,010	↓
Matagorda	293	3,075 ft	1,345–6,340	↓
Galveston	292	4,886 ft	1,797–7,110	↓
Jefferson	260	4,320 ft	892–7,267	↓
Goliad	241	1,700 ft	1–2,300	↓
Harris	239	2,600 ft	647–4,552	↓
Lavaca	226	1,700 ft	1–2,494	↓
San Patricio	214	2,100 ft	1–4,450	↓
Colorado	179	1,966 ft	431–2,971	↓
Nueces	163	2,484 ft	1,428–5,720	↓
Waller	155	1,200 ft	1–2,315	↓
Galveston-Sb	147	6,190 ft	3,000–8,350	↓
Kenedy	110	1,375 ft	300–5,747	↓
Calhoun	100	4,594 ft	1–6,071	↓
Orange	87	3,611 ft	1,080–6,300	↓
Starr	86	1,000 ft	60–2,900	↓
Jim Wells	83	1,700 ft	840–3,599	↓
Duval	80	1,000 ft	446–2,496	↓
Austin	78	1,854 ft	1,458–2,407	↓
Brooks	74	2,400 ft	1,037–4,700	↓
Bee	71	1,330 ft	91–2,259	↓
Hidalgo	71	2,358 ft	1,059–6,022	↓
Willacy	64	5,121 ft	2,350–5,992	↓
Polk	58	1,770 ft	1–3,005	↓
Kleberg	54	2,500 ft	1,000–6,200	↓
Tyler	53	2,334 ft	929–3,240	↓
Jasper	51	3,000 ft	2,300–3,532	↓
Aransas	50	5,150 ft	2,945–6,104	↓
De Witt	48	1,608 ft	1–2,459	↓
Newton	35	3,115 ft	1,615–5,188	↓
Zapata	34	2,000 ft	1,864–2,000	↓
Montgomery	26	1,987 ft	1,798–3,695	↓
Cameron	19	5,740 ft	2,420–8,200	↓
Jim Hogg	17	800 ft	1–4,500	↓
Brazos-Lb	16	6,554 ft	4,360–8,132	↓
Live Oak	10	1,680 ft	819–2,265	↓
San Jacinto	9	2,069 ft	400–3,600	↓
Matgrda Is-Sb	7	5,245 ft	1,700–6,865	↓
Mustang Is-Lb	7	7,010 ft	5,322–7,621	↓
Matgrda Is-Lb	7	5,120 ft	1,680–9,712	↓
Karnes	6	1,005 ft	650–2,902	↓
Webb	5	560 ft	523–804	↓
Brazos-Sb	5	3,973 ft	2,547–7,037	↓

Counties with fewer than 5 wells omitted. Depths are measured depth as filed; typical range is the 10th–90th percentile of reported tops — raw filings contain occasional typo depths, so extremes are not shown.