It took me nearly 15 years of driving by Chimney Rock in the early morning to figure out that during one week or so on either side of the Solstice,
the first light of the rising sun shone upon the exposed sandstone through a small gap in Mesa Verde.
Only lasts about three minutes and then fades away as the sun angles upward and back behind the mesa, to be replaced later by much weaker overall sunrise light.
It only took five more years to get near perfect conditions in which to photograph this event.