Unit ore trains

I have noticed a unit train going east through Nevada on the old SP line.

they are 5 bay hoppers marked RCGX.

I managed to get pictures from an overpass near Deetz NV and noticed that they are half full. Is this the train from Utah?

Yes that is the train from Cedar City, UT.

I know the Cedar City area produces iron ore; can I presume that is what is in the cars? Where is it going?

http://cs.trains.com/TRCCS/forums/p/193429/2111375.aspx#2111375

They run these quite often.

I saw one Thursday, the one I photographed yesterday and then another this morning. this mornings was different. the 3rd unit was not on the rear, but on the front. It seemed to be longer than the others I have seen. Maybe pick up a rear DPU at Reno.

It looks like one of the trains was at the port when the Google Maps car drove through.