CSXT ex. Rio Grande coal hoppers

When did CSXT start receiving these hopper cars? I thought Union Pacific would want to hold onto them.
http://www.railcarphotos.com/PhotoDetai ... toID=10300
http://www.railcarphotos.com/PhotoDetai ... otoID=5131

I dont know just did a trace on it to see if it showed when purchased but no luck. I have been seeing them here in Ohio, for about a year now. Also CSX has purchased some misc ex-CN and other ex-??? lease rotary dump cars, for hauling "stuff" in the 999XXX series. When I get the photos edited I will post.