639 km, 13.5 hours including about 1 hour of rest and one hour on the ferry from Penajam to Balikpapan.
This route is around the outside of southern Kalimantan. The other route goes straight up the middle through the mountains and offers better roads, as well as being shorter. They converge near Tanah Grogot.
For the first three hours there are fairly regular and busy towns so progress is slow.
The route eventually reaches and follows the coast, with pretty scenery and mostly good roads.
When it turns back inland, much if the route is through farmland with 1.5 m grass overhanging the road, sharp rocky mountains that come very close to the road, and some clear streams. I saw people swimming in one creek. Most rivers and streams I’ve seen are far too dirty for that.
The road between Pagatam and Tanah Grogot is pretty bad. The usual thing – mix of dirt and tarmac with thousand of deep, sharp-edged holes. It took about 3 hours.
There are no Pertamina stations along the way and I had 314 km on the trip meter when I reached Tanah Grogot, after topping up 160 km out of Banjarmasin.
Grogot to Penajam is 130 km and took 3 hours.