Although online learning has increased in popularity in higher education, attrition rates in this delivery method are also high. An archival study over a 14-year time period was conducted to (a) compare the drop rates in a face-to-face vs. online introduction to physical geology course and (b) explore possible factors related to the probability of a student dropping a class. Key factors related to higher drop rates were method of delivery, sex, age (preadult, adult), major (STEM, non-STEM), and history of previous drops. This study suggests that building a demographic profile for those who tend to drop physical geology in an online format may be possible and worth further investigation.