By measuring how much carbon-14 remains in a sample, and calibrating that measurement against the known atmospheric record of carbon-14 concentration over time, researchers can calculate when the organism died.

Early radiocarbon dates on the Anzick material produced ages in the range of 10,000 to 11,000 radiocarbon years before present.

These dates were subsequently refined as AMS — accelerator mass spectrometry — radiocarbon dating became available.

AMS dating requires much smaller samples than conventional radiocarbon dating, allowing direct dating of precious materials without destroying large quantities of them, and it tends to be more precise for very old samples.

AMS dates on the Anzick human bone and associated collagen produced calibrated ages of approximately 12,600 to 13,000 calibrated calendar years before present.