UP Yards in Las Vegas - where did it go?

What happened to the large UPRR yard that was located parallel to Main St from Fremont St to Charleston??? I was looking at the arials and it looks rather substantial. In the 1950 view you can see a small round house. Looks like it disappeared in the early 1990s. Now just a 2 track mainline. It started behind the Plaza Hotel and went south.

Look further south to Blue Diamond Rd and you'll see Arden Yard. Look north and you'll see Valley Yard just south of Apex and NW of Nellis. No doubt it would have caused a bottleneck to keep the yard in place with the city wanting an underpass at Charleston and Bonneville.