AMENDMENT NO. 4 TO AGREEMENT AND PLAN OF MERGER THIS AMENDMENT NO. 4 TO AGREEMENT AND PLAN OF MERGER (this "Amendment") dated as of May 5, 2006, by and among Pinnacle Entertainment, Inc., a Delaware corporation ("Pinnacle"), PNK Development 1, Inc., a...Agreement and Plan of Merger • May 8th, 2006 • Aztar Corp • Services-miscellaneous amusement & recreation
