Question: Which county shares a border with the county where the most populous city in the state where WSFN can be found is located?

Knowledge 1: List of municipalities in Georgia (U.S. state)
The largest municipality by population in Georgia is Atlanta with 420,003 residents, and the smallest municipality by population is Edge Hill with 24 residents. The largest municipality by land area is Augusta, a consolidated city - county, which spans 302.47 sq mi (783.4 km), while Edge Hill and Santa Claus are tied for the smallest at 0.18 sq mi (0.47 km) each. [SEP] Knowledge 2: Sno*Drift
Sno*Drift is a rally racing event held in Montmorency County, Michigan, annually, with headquarters in Atlanta, Michigan. The event is currently the first Rally America National Rally Championship event of the season. Currently the event is organized into three distinct rallies: the national championship event covering both days of rallying, and two regional rally events each covering one of the two days. Competitors may be entered in any or all of these events simultaneously. [SEP] Knowledge 3: WSFN
WSFN (790 AM) is a sports radio station in Brunswick, Georgia. WSFN programming is simulcast on WFNS 1350 AM and W279BC 103.7 FM. Southern Media Interactive LLC also owns WSEG at Savannah and WFNS at Blackshear. [SEP] Knowledge 4: Alpena Power Company
Alpena Power Company is a public utility company that provides electricity to most of Alpena County, Michigan, as well as southeastern Presque Isle County and the village of Hillman, in Montmorency County. The headquarters are located in Alpena, Michigan. The company was founded in 1881 by George N. Fletcher.
Knowledge 1: WSFN
WSFN (790 AM) is a sports radio station in Brunswick, Georgia. WSFN programming is simulcast on WFNS 1350 AM and W279BC 103.7 FM. Southern Media Interactive LLC also owns WSEG at Savannah and WFNS at Blackshear. [SEP] Knowledge 2: List of municipalities in Georgia (U.S. state)
The largest municipality by population in Georgia is Atlanta with 420,003 residents, and the smallest municipality by population is Edge Hill with 24 residents. The largest municipality by land area is Augusta, a consolidated city - county, which spans 302.47 sq mi (783.4 km), while Edge Hill and Santa Claus are tied for the smallest at 0.18 sq mi (0.47 km) each. [SEP] Knowledge 3: Sno*Drift
Sno*Drift is a rally racing event held in Montmorency County, Michigan, annually, with headquarters in Atlanta, Michigan. The event is currently the first Rally America National Rally Championship event of the season. Currently the event is organized into three distinct rallies: the national championship event covering both days of rallying, and two regional rally events each covering one of the two days. Competitors may be entered in any or all of these events simultaneously. [SEP] Knowledge 4: Alpena Power Company
Alpena Power Company is a public utility company that provides electricity to most of Alpena County, Michigan, as well as southeastern Presque Isle County and the village of Hillman, in Montmorency County. The headquarters are located in Alpena, Michigan. The company was founded in 1881 by George N. Fletcher.
Knowledge 1: Sno*Drift
Sno*Drift is a rally racing event held in Montmorency County, Michigan, annually, with headquarters in Atlanta, Michigan. The event is currently the first Rally America National Rally Championship event of the season. Currently the event is organized into three distinct rallies: the national championship event covering both days of rallying, and two regional rally events each covering one of the two days. Competitors may be entered in any or all of these events simultaneously. [SEP] Knowledge 2: Alpena Power Company
Alpena Power Company is a public utility company that provides electricity to most of Alpena County, Michigan, as well as southeastern Presque Isle County and the village of Hillman, in Montmorency County. The headquarters are located in Alpena, Michigan. The company was founded in 1881 by George N. Fletcher. [SEP] Knowledge 3: WSFN
WSFN (790 AM) is a sports radio station in Brunswick, Georgia. WSFN programming is simulcast on WFNS 1350 AM and W279BC 103.7 FM. Southern Media Interactive LLC also owns WSEG at Savannah and WFNS at Blackshear. [SEP] Knowledge 4: List of municipalities in Georgia (U.S. state)
The largest municipality by population in Georgia is Atlanta with 420,003 residents, and the smallest municipality by population is Edge Hill with 24 residents. The largest municipality by land area is Augusta, a consolidated city - county, which spans 302.47 sq mi (783.4 km), while Edge Hill and Santa Claus are tied for the smallest at 0.18 sq mi (0.47 km) each.

Answer: Presque Isle County