I present a simple calculation of the expected mean CO brightness temperature from the large-scale distribution of
galaxies during cosmic reionization. The calculation is based on the cosmic star formation rate density required
to reionize, and keep ionized, the intergalactic medium, and uses standard relationships between star formation
rate, IR luminosity, and CO luminosity derived for star-forming galaxies over a wide range in redshift. I find
that the mean CO brightness temperature resulting from the galaxies that could reionize the universe at z = 8 is
T_B ∼ 1.1(C/5)(fesc/0.1)−1μK, where fesc is the escape fraction of ionizing photons from the first galaxies and C is
the IGM clumping factor. Intensity mapping of the CO emission from the large-scale structure of the star-forming
galaxies during cosmic reionization on scales of order 102 to 103 deg^2, in combination with H i 21 cm imaging of
the neutral IGM, will provide a comprehensive study of the earliest epoch of galaxy formation
