I live in Las Vegas, Nevada. This morning an hour before sunrise I noted the regular stars and planets, including Venus and also low on the SW horizon a bright object, brighter than Venus. It remained in view well after Venus disappeared and continued to be seen well after sunrise. I couldn't find any references to this object anywhere on the net. Could it be a low earth satelite, or something else?
This might be Mars. It should be behind us, now. Might also be the dark twin but I think as black rock it would not be seen as you describe. There are no planets in the SW at the time and place you describe, all are East or not in the dome at all. I'll bet you saw Mars! That's exactly where it should be at this time, in a halted Earth orbit!