{"name":"Calvert Drilling Drilling Activity in Saline County, Illinois","publisher":"Buckhead Energy","url":"https://www.buckheadenergy.com/operators/calvert-drilling/illinois/saline-il","license":"https://creativecommons.org/licenses/by/4.0/","dataAsOf":"2026-08-06","source":"Public state oil & gas well-header records (permits, spuds, completions).","operator":"Calvert Drilling","operatorSlug":"calvert-drilling","state":"IL","county":"Saline","totalWells":51,"producingWells":0,"permits24mo":0,"spuds24mo":0,"ducCount":0,"topFormation":null,"rankInCounty":7,"firstPermitDate":"1970-01-01","lastPermitDate":"1994-02-25"}