Radiocarbon dating has shown that most of the burials took place between 13,000 and 10,000 years ago. The youngest burial was about 6,500 years old. Optically stimulated luminesence (OSL) dating in 2003 showed the burials were between 22,000 and 19,000 years old. However, these dates have been questioned due to the difficulty of making sure the dated sand is the same age as the actual burials. Dating research on bones from other sites in the region such as Nacurrie and Coobool Creek, support the 13,000 to 9,000 date range for Kow Swamp.