This report presents the results of in-mine studies to determine the severity of dust sources in conventional mining operations. Three underground coal mines were surveyed using gravimetric samplers and continuous dust monitors, and two mines were surveyed using only monitors. Data on dust control methods were acquired during the survey. The results indicated that cutting, drilling, and loading out were the dustiest operations during a conventional mining cycle. Roof bolting, shot firing, and product transport were less severe dust sources.