Complex sentence: The Colorado Chautauqua, located in Boulder and started in 1898, is the only surviving Chautauqua west of the Mississippi River and one of three remaining in the United States as of 2006.
Split into simpler sentences: The Colorado Chautauqua, located in Boulder and started in 1898, is the only Chautauqua west of the Mississippi River still continuing in operation. It is one of three remaining in the United States as of 2006.