erc: who: Geological Survey (U.S.) what: Coryell Quadrangle when: 2010 where: https://texashistory.unt.edu/ark:/67531/metapth210597/ erc-support: who: University of North Texas Libraries what: Permanent: Stable Content: when: 20081203 where: https://texashistory.unt.edu/ark:/67531/