Lake Russell State Park Lodging. This is on the GA side but shouldn't be more than a 20 min ride to Calhoun Falls state park. It's really nice here as well. 

https://gastateparks.reserveamerica.com/campsiteFilterAction.do?sitefilter=ALL&startIdx=0&contractCode=GA&parkId=530188&_gl=1*xfyjek*_ga*MTIwODM2MzQwMi4xNzM4MDkxOTI0*_ga_NY38CG84RB*MTczODA5MTkyMy4xLjAuMTczODA5MTkyMy4wLjAuMTgwMDQ0NTM5OQ..