Why These Three Areas?

Tonight, we pick back up where we left off. Judah had captured the city of Jerusalem, and they press on in their efforts to take ownership of the land as God had directed. "9 After that, Judah went down to fight against the Canaanites living in the hill country, the Negev and the western foothills." (Judges 1:9 HCSB) Now we read this passage of scripture, and our general inclination is to just go on to the next verse. But have you ever wondered why these three areas? Why are these three zones called out specifically? Why where these so important to Judah's conquest?