That was Cerro Gordo Road (Inyo Mtns. a little west of Death Valley) leading down from the old town of Cerro Gordo to Lee Flat/Saline Valley after the summer 2013 rains rearranged the road a bit. I'll bet they've probably taken a road grader through there by now though, as I understand that trail was pretty smooth before the rains.
The top pic was west of the salt tramway up on that same ridge (near the Burgess mine) and requires traversing a narrow shelf road and some fairly steep switchbacks to get to it (I wouldn't recommend it in your F-350 at least until you have some experience and know your truck's capabilities better).
If you're looking for places to go, DV and many of the surrounding areas is certainly a great place to start. Lots of trail opportunities for your F-350 ranging from easy to what I'd call moderate (though others in unmodified rigs might call them 'extreme'... this is simply a matter of perspective
). There is lots of old mining history to check out in the area too.