X0101 EFFECT 33 LIVE 2019-06-18 0001193125-19-173845 POS AM 0001071993 CONTANGO OIL & GAS CO 333-215784 0001596386 CONTANGO VENTURE CAPITAL CORP 333-215784-10 0001596239 CONTANGO ALTA INVESTMENTS, INC. 333-215784-09 0001596378 CONTARO CO 333-215784-08 0001642326 CONTANGO ROCKY MOUNTAIN INC 333-215784-07 0001596376 CONTERRA CO 333-215784-06 0001596374 CONTANGO OPERATORS, INC 333-215784-05 0001436080 Contango Energy CO 333-215784-04 0001550972 CRIMSON EXPLORATION OPERATING, INC. 333-215784-03 0000813779 CRIMSON EXPLORATION INC. 333-215784-02 0001596470 CONTANGO MINING Co 333-215784-01