An example 21-cm brightness temperature field at shown at redshifts 6, 7, and 8 (left to right) with galaxies overlaid on zoomed insets (black). Detectable galaxies at these redshifts preferentially reside in ionized regions, with the brightest, most biased galaxies residing in the largest ionized bubbles. The top row shows slices of the full gigaparsec volume used in this study, while the bottom row zooms into a 200 Mpc corner for clarity. Both the brightness temperature and galaxy fields were generated simultaneously using 21cmFASTv4.