For over 20 years, the seasonal regression of the martian polar caps has been regularly observed from the Hida and Kwasan Observatories in Japan and the Bosscha Observatory in Indonesia (e.g., Iwasaki et al., J. Geophys. Res., 95, 14751, 1990). Some of the interesting features which have been observed include a temporary halt observed in the regression of the north polar cap; observed variations in the regression of both polar caps with longitude; and isolated outliers of ice such as the Mountains of Mitchell. Simulations of the regression of the martian polar caps obtained via a complex energy balance computer model (e.g., Lindner, J. Geophys. Res., 98, 3339, 1993) have been compared to the dataset. We find that variations in terrain and surface roughness can easily account for these interesting features in the data. This material is based on work supported by the National Science Foundation under Grant No. INT-9402136. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect those of the National Science Foundation.