24 BXD RI (recombinant inbred) strains were analyzed for loci associated with bone mineral density (BMD) and body weight in 12-week-old female animals. Progenitor strain C57BL/6 exhibits greater bone mass than progenitor strain DBA/2 at 84 days of age, but body weight is very similar between the 2 strains. After screening over 1500 informative markers on a BXD mapping panel 10 provisional QTLs associated with BMD mapped to 9 different chromosomes and await confirmation. Two of the most significant BMD QTLs (P = 0.0007), Bomd1, mapped to mouse chromosome 7 at 44 cM (in linkage with D7Mit234a), and Bomd2, mapped to mouse Chromosome 14 at 2 cM (in linkage with Ptprg). Possible candidate genes for Bomd1 are the insulin-like growth factor I receptor (Igf1r), parathyroid hormone (Pth), and calcitonin (Calca, previously Ct). A possible candidate gene for Bomd2 is bone morphogenetic protein 4 (Bmp4).