Complex sentence: At that time, a section on the east end from Black Mountain Rd to Camino Del Sur opened, but it took until July 19,2004, to join the west and east ends of the freeway.
Split into simpler sentences: At that time, a section on the east end from Black Mountain Rd to Camino Del Sur opened. It took until July 19,2004, to join the west and east ends of the freeway.