A stem dissection technique for dating branch mortality and estimating past crown recession was evaluated on 28 Douglas-fir trees from permanent plots in Oregon and Washington. Repeated height to live crown measurements over the past 15 years on each of the 28 trees provided a basis for comparison with the branch mortality dating technique. After each tree was felled in a scheduled thinning, heights to 10-15 consecutive branch whorls below crown base were measured. Sections containing the whorls were then removed and dissected on a band saw to expose longitudinal sections through the encased dead branches. Discontinuities between branch and bole growth rings, corresponding to the delineation between tight and loose knot zones, allowed estimation of years since branch mortality. Past heights to live crown were reconstructed from the branch mortality estimates and whorl heights. Backdated crown base positions corresponded closely with the 15-yr field remeasurements. For. Sci. 33(4):858-871.