Complex sentence: Population-wise, it is the fourth-largest city in the DMA, but as it is new, many people even in the DMA do not recognize the area by the name "Centennial", often confusing it with neighboring cities, notably Littleton and Aurora.
Split into simpler sentences: Population-wise, it is the fourth-largest city in the DMA. As it is new, many people, even in the DMA, do not recognize the area by the name "Centennial", but more often it is confused with neighboring cities, notably Littleton and Aurora.