Complex sentence: In March of 1770 Felipe de Barri, in Baja California, was the made governor of both Baja and Alta California (1770-1775), but as Monterey was far away, Fages was free to run Alta as acting governor.
Split into simpler sentences: In March of 1770 Felipe de Barri, in Baja California, was made governor of both Baja and Alta California (1770-1775). But, since Monterey was far away, Fages had free rein to run Alta as acting governor.