Sun Temple is believed to be among the latest constructed of all the
aboriginal buildings in the park, probably contemporaneous with late
building activities in Balcony House, Spruce Tree House, and Cliff
Palace.
Because of the absence of timbers or roof beams it is impossible to
tell when Sun Temple was begun, how long it took for its construction,
or when it was deserted. There are indications that its walls may
never have been completed, and from the amount of fallen stones there
can hardly be a doubt that when it was abandoned they had been carried
up in some places at least 6 feet above their present level. The top
of the wall had been worn down at any rate 6 feet in the interval
between the time it was abandoned and the date of excavation of the
mound. No one can tell the length of this interval in years.
We have, however, knowledge of the lapse of time, because the mound
had accumulated enough soil on its surface to support growth of large
trees. Near the summit of the highest wall in the annex there grew a
juniper tree of great antiquity, alive and vigorous when excavation
work was begun. This tree undoubtedly sprouted after the desertion of
the building and grew after a mound had developed from fallen walls.
Its roots penetrated into the adjacent rooms and derived nourishment
from the soil filling them.
Necessarily, when these roots were cut off the tree was killed. It was
then cut off about a foot above the ground, the stump remaining. A
cross section of this stump was examined by Gordon Parker, supervisor
of the Montezuma National Forest, who found that it had 360 annual
rings without allowing for decayed heartwood which would add a few
more years to its age.
It is not improbable that this tree began to grow on the top of the
Sun Temple mound shortly after the year 1540, when Coronado first
entered New Mexico. How long an interval elapsed for crumbling walls
to form the mound in which it grew, and how much earlier the
foundations of the ruined walls were laid, no one can tell. A
conservative guess of 350 years for the interval between construction
and the time the cedar began to sprout would carry the antiquity of
Sun Temple back to about 1200 A.D.