  The epoch of reionization (EoR) sets a fundamental benchmark in cosmic
structure formation, corresponding to the formation of the first luminous
objects that act to ionize the neutral intergalactic medium (IGM). Recent
observations at near-IR and radio wavelengths imply that we are finally probing
into this key epoch of galaxy formation at $z \ge 6$. The Square Kilometer
Array (SKA) will provide critical insight into the EoR in a number of ways.
First, the ability of the SKA to image the neutral IGM in 21cm emission is a
truly unique probe of the process of reionization, and is recognized as the
next necessary and fundamental step in our study of the evolution of large
scale structure and cosmic reionization. Second, study of HI 21cm absorption
toward the first radio loud objects probes small to intermediate scale
structure in the neutral 'cosmic web', as well as HI in the first collapsed
structures (proto-disks and mini-halos). And third, the incomparable
sensitivity of the SKA allows for the study of the molecular gas, dust, and
star formation activity in the first galaxies, as well as the radio continuum
emission from the first accreting massive black holes. Such objects will be
obscured at optical wavelengths due to absorption by the neutral IGM.
