This area contains hundreds of thousands of acres of remote wilderness. Many locations, including those in and around the Chattooga River, even where there is nearby road access, are easily a ½ hour from the nearest emergency medical care. Emergencies at locations such as Lake Tugaloo can take 2 hours for emergency medical care to arrive at the landing.
Also, there are large blocks of area, including the river corridor, where cell phones do not receive reception. You will still be required to hike out to an area accessible to a tower.
If you do have an emergency, be prepared to provide 911 with very specific instructions on your location, even for well-known locations such as Bull Sluice.
Be aware and use appropriate caution.
Emergency numbers for the following communities are as follows:

Oconee County, SC
Oconee Memorial Hospital Emergency Medical Services
(864) 886-7188
Oconee County Sheriff's Office
(864) 638-4111

Rabun County, GA
Rabun County Memorial Hospital
(706) 782-0465

Macon County, NC
Highlands-Cashiers Hospital
(828) 526-1200