(1) The term "organized camp" also does not include any camp site in a county park in a county with a population of more than four million established pursuant to the provisions of this subdivision for the purpose of short-term group camping, which is hereby defined as camping by any group of people for a period of not more than 72 consecutive hours. The certificate of the director of parks and recreation of such county shall be conclusive as to the fact that a camp site has been established for the purpose of short-term group camping.
This subdivision shall remain operative only until January 1, 1981, and shall have no force or effect on or after such date, unless a later enacted statute which is chaptered before January 1, 1981, deletes or extends such date.