<ACCESSION-NUMBER>0000788965-18-000027 <TYPE>8-K <PUBLIC-DOCUMENT-COUNT>5 <PERIOD>20180806 <ITEMS>2.02 <ITEMS>5.02 <ITEMS>9.01 <FILING-DATE>20180807 <DATE-OF-FILING-DATE-CHANGE>20180806 <FILER> <COMPANY-DATA> <CONFORMED-NAME>HALLADOR ENERGY CO <CIK>0000788965 <ASSIGNED-SIC>1220 <IRS-NUMBER>841014610 <STATE-OF-INCORPORATION>CO <FISCAL-YEAR-END>1231 </COMPANY-DATA> <FILING-VALUES> <FORM-TYPE>8-K <ACT>34 <FILE-NUMBER>001-34743 <FILM-NUMBER>18996065 </FILING-VALUES> <BUSINESS-ADDRESS> <STREET1>1660 LINCOLN ST STE 2700 <CITY>DENVER <STATE>CO <ZIP>80264 <PHONE>3038395505 </BUSINESS-ADDRESS> <MAIL-ADDRESS> <STREET1>1660 LINCOLN STREET <STREET2>SUITE 2700 <CITY>DENVER <STATE>CO <ZIP>80264 </MAIL-ADDRESS> <FORMER-COMPANY> <FORMER-CONFORMED-NAME>HALLADOR PETROLEUM CO <DATE-CHANGED>19920703 </FORMER-COMPANY> <FORMER-COMPANY> <FORMER-CONFORMED-NAME>KIMBARK OIL & GAS CO /CO/ <DATE-CHANGED>19900102 </FORMER-COMPANY> <FORMER-COMPANY> <FORMER-CONFORMED-NAME>KIMBARK INC <DATE-CHANGED>19860624 </FORMER-COMPANY> </FILER>