EXHIBIT 2.1 FIRST AMENDMENT TO PURCHASE AND SALE AGREEMENT ---------------------------------------------- THIS FIRST AMENDMENT TO PURCHASE AND SALE AGREEMENT ("Amendment") is entered into this 22nd day of May, 1998, by and between Amoco Production...Purchase and Sale Agreement • June 5th, 1998 • Howell Corp /De/ • Wholesale-petroleum & petroleum products (no bulk stations) • Wyoming
