County Seat
Sherman Is the County Seat and Largest City in Grayson County
Sherman serves as the county seat of Grayson County, where county government offices, courts, and the appraisal district are located.
Sherman sits about 65 miles north of Dallas on U.S. Highway 75. It has been the county seat since Grayson County was established in 1846. Most county government functions are based here, including the county courthouse, the appraisal district, and the tax office.
Denison is the second-largest city in the county. Other communities include Whitesboro, Van Alstyne, Pottsboro, and Whitewright. If you need to file documents with the county, pay taxes, or visit a county court, Sherman is where to go.
Source to confirm: Handbook of Texas — Grayson County