We arrived at the Argentinean border controls at 9:20am and at Bolivian controls at 10 am. As usual, I stayed in the car (with the engine running because it was -5 C/23 F degrees). Dimitri did all of the paperwork (even getting my passport stamped without my having to show my face). I guarded all of the stuff in our car. We were given 90 day permissions to stay in Bolivia for ourselves and for the car. We were in the border town of Villazon, Bolivia at 10:25am. We left 11 am (after stopping to change money and buy a map--that turned out to be fairly useless).
We had done lots of research before deciding to come to Bolivia. We asked specific questions of the Bolivian Consul in Salta about the condition of the road and whether it was paved from La Quiaca to Tarija. He said all but 70 km were paved. We asked others too and got conflicting information. We read that there were road blockades by miners near Potosi and strikes in other areas. When we were in Cafayate, Argentina at Patios de Cafayate, we met two Bolivian couples who were driving back to Santa Cruz. We asked them about the roads to Santa Cruz and they said they were all paved. We sent them an e-mail asking about the route we proposed to take to Tarija but got no reply.
After getting (or not getting) all this information we still decided to drive through Bolivia, the Bolivian Consul saying we would have no problems and the roads were good and paved with blacktop. Well, 2 inches from the main square in Villazon, the road to Tarija became a dirt road. It was the dry season so it was hard-packed and there weren't too many obstructions but lots of ups and downs.
Still, Dimitri had to do all of the driving --185 km that took 5 hours at an average speed of 35 kph. I didn't feel comfortable driving on that kind of surface. Until the road intersected the one coming south from Potosi and turned to Tarija, there were only a handful of other cars, trucks and buses. Without other traffic the road was 'do-able'.
We saw some spectacular scenery as we entered a gorge (quebrada) and descended to the bottom of it. We followed the river bed at the bottom of the gorge for many kilometers and there were a few settlements. None looked too poor. Then we started the ascent. It was actually easier than the descent because the surface of the road was like talcum powder in spots and they was slippery. More than once, we were glad that we decided in Bariloche to keep the Michelin Alpine snow tires on the car. They give us added traction.
When we started meeting trucks on the road we were on a narrow ledge of the gorge with no verge or shoulder. The fine dust the trucks threw off was blinding. Passing them was a challenge. When we got to the top of the Cordillera de Sama we thought we had it made. There was a plain with the salt lakes that are a part of the Sama Biological Reserve in the Tajzara Section. We were at about 3700 masl. We saw lots of alpacas or llamas (we can't tell the difference) on the puna. The vegetation was a small desert bush called thola and the spikey paja brava. New ages consider this area a power point. But we thought we were finished with the worst. But we weren't; the descent into Tarija was a long, narrow ledge with lots of truck traffic. It just didn't end. But the time we arrived at 3:30 pm, we were both exhausted (even though I wasn't driving). We learned the next day that if we had driven east in Argentina to the border crossing at Aguas Blancas we would have had paved road all the way to Tarija. Oh well, all's well that ends well.