Big Creek or Vickery Creek is a 26.5-mile-long stream in Forsyth and Fulton counties in Georgia. The creek mouth into the Chattahoochee River is located at the southern border of Roswell where State Route 9 crosses the river. Its source is located just north of the intersection of Georgia State Route 9 and Georgia State Route 20, in Forsyth County, about 1 mil…Big Creek or Vickery Creek is a 26.5-mile-long stream in Forsyth and Fulton counties in Georgia. The creek mouth into the Chattahoochee River is located at the southern border of Roswell where State Route 9 crosses the river. Its source is located just north of the intersection of Georgia State Route 9 and Georgia State Route 20, in Forsyth County, about 1 mile directly south of downtown Cumming.