The calibrated range for the Buhl date, using the calibration curves available at the time of the 1998 publication and updated in subsequent recalibrations, comes out to something in the range of approximately 12,690 to 12,145 calibrated years before present — the range that the Jazwa et al.

2021 paper cited when describing what the date implies “if the date is reliable, which it probably is not.”

The uncertainty in that calibrated range is already substantial: roughly 500 calibrated years spans the plausible range for the date as measured.

Add the additional uncertainty from the potential freshwater reservoir effect — which could shift the date by anywhere from near zero to perhaps 1,500 radiocarbon years in severe cases — and the calendar age range for the burial becomes very wide indeed.

This is why the Buhl Woman is sometimes described as “approximately 12,500 years old” and sometimes as “approximately 11,000 years old” in different accounts: the first figure reflects the calibrated midpoint of the uncorrected date; the second reflects the older, pre-calibration treatment of the raw radiocarbon date as an approximate age estimate.