Thanks for that post about Downtown! But this is actually not the first time that White Castle Burgers have been served in Downtown LV. One of the Downtown LV casinos long ago (at least at the time when the Video for the U2 song "I Still Haven't Found What I'm Looking For" was being filmed) did have them for sale -- one of the casino signs says that. That video has them walking up and down Fremont Street before the FSE was installed and Fremont Street was still open to vehicles.
YouTube has the Video for U2's "I Still Haven't Found What I'm Looking For" so check that out!
RecVPPlayer
P.S. -- I want to make it clear that I'm not saying that there was a White Castle location in Downtown but that one of the casinos did have White Castle burgers for sale.