Complex sentence: The 1999 United States Open Championship was the 99th U.S. Open, held from June 17-20 at Pinehurst Resort Course No.2 in Pinehurst, North Carolina.
Split into simpler sentences: The 1999 United States Open Championship was the 99th U.S. Open. The event was held from June 17-20 at Pinehurst Resort, Course No.2 in Pinehurst, North Carolina.