  The extreme outer Galaxy (EOG) has a very different environment from that in
the solar neighborhood, with low metallicity (less than -0.5 dex), much lower
gas density, and small or no perturbation from spiral arms. The EOG is an
excellent laboratory for the study of the star formation processes that
happened during the formation period of the Galaxy. In particular, the study of
the EOG may shed light on the origin and role of the thick disk, whose
metallicity range matches well with that of the EOG. We show an example of a
molecular cloud in the EOG (Digel's Cloud 2), which is located at R_g ~ 20 kpc
beyond the Outer arm. Based on our NIR and 12CO data as well as HI, radio
continuum, and IRAS data in the archives, we examined the detailed star
formation processes in this unique environment, especially the supernova
triggered star formation, which should have been the major star formation mode
during the halo and thick disk formation.
