Complex sentence: It climbs southwards from Camden through the Razorback Ridge to Picton, then begins to climb through Tahmoor and Bargo to reach the Southern Tablelands and rejoin the present route of the Hume Highway at Aylmerton, 6 km north of Mittagong.
Split into simpler sentences: It climbs southwards from Camden, goes through the Razorback Ridge to Picton, and then climbs to Tahmoor and Bargo. It reaches the Southern Tablelands and rejoins the present Hume Highway at Aylmerton, 6 km north of Mittagong.