Study Unit


Inside Date (A.D.)

Outside Date (A.D.)

Tree Species




Tree-Ring Laboratory No.


PD = provenience designation; FS = field specimen; PL = point-location number.

Date symbol explanations (from the Laboratory of Tree-Ring Research, Tucson, Arizona):

  • B Bark is present.
  • r Less than a full section is present, but the outermost ring is continuous around the available circumference.
  • v A subjective judgment that, although there is no direct evidence of the true outside on the sample, the date is within a very few years of being a cutting date.
  • vv There is no way of estimating how far the last ring is from the true outside; many rings may be lost.
  • + One or a few rings may be missing near the outside whose presence or absence cannot be determined, because the series does not extend far enough to provide adequate cross dating.
  • ++ A ring count is necessary beyond a certain point in the series because cross dating ceases.