0000932384-97-000146 10-K/A 2 19961231 19970605 NASD BASIN EXPLORATION INC 0000827795 1311 841143307 DE 1231 10-K/A 34 000-20125 97619685 370 SEVENTEENTH ST STE 1800 DENVER CO 80202 3036858000 370 SEVENTEENTH STREET SUITE 1800 DENVER CO 80202 10-K/A 1 000093238497000146-001-seq1-10-k-a.txt AMENDMENT TO FORM 10-K EX-10.21 2 000093238497000146-002-seq2-ex-10-21.txt PURCHASE AND SALE AGREEMENT