The ISM of z>~6 galaxies is a crucial element for understanding many important probes of cosmic reionization, such as recently discovered Lyman-break systems in the UDF, the evolution of Lyman-alpha emitters, Swift gamma ray bursts, and intensity mapping of galactic emission lines with ALMA, which can improve the reliability of 21cm tomography. I will present a new, fully-analytic framework for describing the ISM and molecular cloud properties of reionization epoch galaxies that includes physical processes from an enormous range of distance scales---from the tens of megaparsec regions over which cosmic variance operates to the tens of parsec-sized photo-dissociative regions inside molecular clouds---a span typically beyond the reach of numerical simulations. I will discuss the observational consequences of such a model, in particular, examining whether recent Chandra data can constrain the way gas is transported through the disk and making realistic predictions for detecting carbon emission lines with the JVLA and ALMA.
