Selected Mg II absorption line systems in each of the 19 spectra comprising the high‐resolution sample, S1. Each panel (normalized flux vs. rest‐frame velocity in km s⁻¹) shows the strongest Mg II doublet in the spectrum, unless an absorption redshift is within [z_min, z_max] of a cluster in the same LOS, in which case the latter system is plotted. Associated systems (﹩z_{\mathrm{abs}\,}\sim z_{\mathrm{em}\,}﹩) were not considered.