Nucleotide sequences of the mitochondrial D-loop region were examined in three wild rodents (Apodemus argenteus, Apodemus speciosus, and Myodes smithii) on the northern slope of Mt. Fuji, the highest mountain in Japan, to elucidate the past evolutionary and present anthropogenic processes shaping their genetic diversity. Nucleotide diversity, median-joining network, and mismatch distribution analyses suggested that A. argenteus has multiple divergent lineages, possibly due to multiple previous expansion events, whereas A. speciosus and M. smithii are younger lineages that could be derived from single expansion events. These findings indicate that Mt. Fuji plays an important role as a reservoir maintaining lineages through multiple past expansion events. Artificial infrastructure also affected the genetic diversity of the two Apodemus species, as populations of these species on the two sides of the Fuji Subaru Line roadway were genetically distinct. To construct a proper conservation strategy based on genetic diversity, we suggest that the past and present contributors to genetic diversity must be clarified. Such clarification is especially important for the Mt. Fuji environment, which harbors rich biodiversity but also incurs much human impact as a national park.