Wrong, sorry, thank you for playing.
Geauga Lake's parent company, Premier Parks, acquired Six Flags in 1998. Note the direction of acquisition.
Premier Parks acquired Geauga Lake sometime before the 1996 season. It may have been as early as late 1994, but I am not certain of the exact date.
The conversion to the Six Flags brand name, of course, happened for the 2000 season.
--Dave Althoff, Jr.