O.C.G.A. § 12-3-299

The North Georgia Mountains Authority shall exercise all of its powers and engage in the business of its projects within the territorial boundaries and jurisdiction of Banks, Catoosa, Chattooga, Cherokee, Dade, Dawson, Fannin, Forsyth, Franklin, Gilmer, Gwinnett, Habersham, Hall, Lumpkin, Murray, Pickens, Rabun, Stephens, Towns, Union, Walker, White, and Whitfield counties and such other counties as may from time to time be admitted by resolution of the authority.