Texas Formations

Formation tops as reported by operators on W-2/G-1 completion filings, normalized across spelling variants and aggregated statewide. Each formation page maps every reported penetration, breaks depths down by county, and exports to CSV for use in mapping software.

FormationWells w/ TopsCountiesMedian Depth
San Andres88,915494,213 ft
Yates67,564422,561 ft
Wolfcamp57,430918,358 ft
Spraberry57,142367,309 ft
Clear Fork55,595625,704 ft
Grayburg48,638363,965 ft
Austin Chalk44,084878,438 ft
Queen40,207483,407 ft
Strawn32,4421017,825 ft
Eagle Ford31,906699,522 ft
Wilcox31,390915,150 ft
Dean30,176388,300 ft
Glorieta29,934514,965 ft
Rustler26,698401,509 ft
Seven Rivers25,992332,721 ft
Canyon23,894956,167 ft
Barnett22,692777,126 ft
Travis Peak22,180557,400 ft
Olmos21,583255,337 ft
Marble Falls20,489486,296 ft
Pettit20,392447,195 ft
Caddo20,370594,214 ft
Frio19,235614,601 ft
Santa Rosa17,459321,000 ft
Atoka16,014936,870 ft
Escondido15,547243,931 ft
Anacacho15,251308,783 ft
Cotton Valley15,008389,212 ft
Yegua14,953553,155 ft
Queen City14,445543,003 ft
Cherry Canyon13,825115,397 ft
Bone Spring13,559108,253 ft
Delaware12,662104,466 ft
Rodessa11,706486,616 ft
Bell Canyon11,19184,570 ft
Navarro10,929695,648 ft
Carrizo10,155423,832 ft
Cisco10,054883,584 ft
Brown Dolomite9,790222,986 ft
Tubb9,332456,042 ft
Bossier9,1403411,155 ft
James Lime8,967436,978 ft
Mississippian8,809978,146 ft
Base Cretaceous (marker)8,37141793 ft
Pecan Gap8,063736,950 ft
Catahoula7,831463,300 ft
Ellenburger7,5261106,676 ft
Wichita-Albany7,378616,030 ft
San Miguel7,332174,621 ft
Vicksburg7,294486,310 ft
Buda7,273726,290 ft
Miocene (undifferentiated)7,190612,326 ft
Gunsight7,022371,374 ft
Reklaw7,015333,790 ft
Glen Rose6,987674,790 ft
Woodbine6,842544,623 ft
Pennsylvanian6,529968,007 ft
Palo Pinto6,346463,035 ft
Coleman Junction6,344372,350 ft
Midway6,255715,054 ft
Paluxy6,082494,238 ft
Granite Wash5,9253710,531 ft
Brushy Canyon5,75986,800 ft
Devonian5,4033710,077 ft
Douglas5,238136,486 ft
BMA5,201356,626 ft
Cleveland5,013127,709 ft
Taylor4,996809,668 ft
Bend4,995575,774 ft
Massive Anhydrite (marker)4,393396,327 ft
Tonkawa4,117107,164 ft
Tansill4,107262,300 ft
Tannehill3,751281,570 ft
San Angelo3,597292,520 ft
Leonard3,542365,868 ft
Castile3,50072,638 ft
Nacatoch3,474421,536 ft
Morrow3,369398,614 ft
Red Cave3,221181,891 ft
Sparta2,997432,350 ft
Georgetown2,984657,689 ft
Jackson2,966482,972 ft
Forestburg2,868107,375 ft
Holt2,842104,943 ft
Fusselman2,6793510,460 ft
Permian (undifferentiated)2,671592,511 ft
Saddle Creek2,658321,854 ft
Edwards2,621638,180 ft
Panhandle Lime2,614172,302 ft
Duffer2,587193,850 ft
Lamar2,578124,712 ft
Woodford2,5124810,612 ft
Viola2,503288,084 ft
Wills Point2,20749,955 ft
Anahuac2,200414,459 ft
Kansas City2,157107,040 ft
Big Saline2,036244,694 ft
Cook Mountain2,034403,954 ft
Thomas Sand2,032111,228 ft
Salado1,996281,488 ft
Greta1,947154,450 ft
Jo Mill1,902157,660 ft
Blossom1,740252,198 ft
Bryson1,714113,466 ft
Haynesville1,7103011,670 ft
Marmaton1,694127,179 ft
Sligo1,676406,169 ft
Sub-Clarksville1,630285,950 ft
Goodland1,535343,794 ft
Cline1,496259,037 ft
Oswego1,469810,126 ft
Des Moines1,4212110,764 ft
Oakville1,400332,750 ft
McKnight1,332103,198 ft
White Dolomite1,303122,980 ft
Moore County Lime1,193143,074 ft
Lagarto1,185111,500 ft
Del Rio1,169444,890 ft
Silurian (undifferentiated)978249,182 ft
Hood967125,568 ft
Chester964338,395 ft
Avalon79767,503 ft
Smithwick787285,591 ft
Red Bluff76333,900 ft
Bartosh72293,520 ft
Caprock720191,063 ft
Simpson716419,362 ft
Montoya6142711,086 ft
KMA561123,794 ft
Abo525247,550 ft
Toborg4322400 ft
McKee34898,604 ft
Waddell33998,475 ft
Weches307281,020 ft
Smackover2902711,325 ft
Wolfe City2558784 ft
Kiamichi236265,602 ft
Buckner1901611,000 ft
Capitan15273,500 ft
Pearsall148189,330 ft
Ozan1091210,692 ft
Goliad5014546 ft
Maness40123,862 ft
Yeso4067,003 ft
Walnut3774,312 ft

Source: RRC wellbore records (dbf900), operator-reported tops on completion filings. Formations with fewer than 25 wells are omitted from this index. Depths are measured depth.