{"name":"Union Oil Company Of California Drilling Activity in San Mateo County, California","publisher":"Buckhead Energy","url":"https://www.buckheadenergy.com/operators/union-oil-company-of-california/california/san-mateo","license":"https://creativecommons.org/licenses/by/4.0/","dataAsOf":"2026-08-06","source":"Public state oil & gas well-header records (permits, spuds, completions).","operator":"Union Oil Company Of California","operatorSlug":"union-oil-company-of-california","state":"CA","county":"San Mateo","totalWells":18,"producingWells":0,"permits24mo":0,"spuds24mo":0,"ducCount":6,"topFormation":null,"rankInCounty":2,"firstPermitDate":"1956-06-26","lastPermitDate":"1960-10-03"}