The Collaborative International Dictionary of English v.0.48:
countywide \countywide\ adj. including or occurring in all parts of a county; as, a countywide war on drugs; countywide elections. [WordNet 1.5]WordNet (r) 3.0 (2006):
countywide adj 1: occurring or extending throughout a county; "a countywide war on drugs"; "countywide elections"