Archaeologists in the Clam Garden Network have determined that Indigenous people started constructing clam gardens at least 4000 years ago.  They have determined this using several methods, most of which involve digging either under a wall or into the garden terrace.  In order not to have the excavation units flooded, archaeologists are limited to working during the lowest low tide windows of the year.  These tides only occur during daylight for a 3-hour window, 5 days in each of May, June, and July and for 3 days in August.  This amounts to only 54 possible hours in which to conduct archaeological field work.