As most of you know King Kobra was the first in a very long series of Schwarzkopf
Shuttle Loop Rides. Of course it is still operational in Brazil at
Hopi Hari, so if you feel like making the trip you can still ride it.
That all being said, the last of its kind and the only one in the US still standing in its original location is
Montezooma's Revenge at
Knott's Berry Farm.
Allegedly Motezooma's Revenge is one of the parks favorite attractions and it does not appear to be going anywhere. From what I can tell, I think they have almost Nessie like attachment to her. (please to not be confused, I would never dare compare a shuttle loop to Nessie, Nessie is of course royalty)
There are a couple of differences between KK and MR. KK was pure counter weight and MR is a flywheel. MR benefited from being the last or nearly the last of her kind, and so had many years of design experience behind her. KK was breaking ground and has, among other things a shorter track.
Either way, it is nice to know that the first and last can still both be ridden!
Here is a link to some images of MR.
Montezooma's Revenge Images