Encompassing some 37433 sqmi , the diocese comprises the following 29 counties: Andrews, Brown, Callahan, Coke, Coleman, Concho, Crane, Crockett, Ector, Glasscock, Howard, Irion, Kimble, Martin, McCulloch, Menard, Midland, Mitchell, Nolan, Pecos, Reagan, Runnels, Schleicher, Sterling, Sutton, Taylor, Terrell, Tom Green, and Upton.