Complex sentence: Wasilla is the largest town in the Mat-Su Valley; at the conclusion of Palin's tenure as mayor in 2002, the city had about 6,300 residents, and it is now the fifth largest city in the state.
Split into simpler sentences: Wasilla is the largest town in the Mat-Su Valley. At the conclusion of Palin's tenure as mayor in 2002, the city had about 6,300 residents, and it is now the fifth largest city in the state.