Slide 1

Sink Hole History – 1950s

n1957: Lime sink opened

nSeptember 1982: Porter Hole #1 opened, plugged itself

nSeptember 1999: Porter Hole #2 opened and stayed opened until 2005

nSummer 2007: Porter Hole #1 reopened


	1957: Lime sink opened – artificially filled
	September 1986: Porter Hole #1 opened, plugged itself in about two weeks
	September 1999: Porter Hole #2 (50 feet south of Porter Hole #1) opened and stayed opened until 2005
	Summer 2007: Porter Hole #1 reopened and has filled with clay and limestone fragments, integrity of plug unknown