I knew it could be removed. I just never had a reason to remove it.
The other molex plugs were in the bottom of the case. It just never occurred to me that a plug would be in the middle of the wire bundle. I took it off looking for a plug that may have slipped back where I couldn't see it on the bottom.
I also found a little 2-wire plug in the middle of the wire bundle. Both male and female plugs are there, but they are unplugged. What is it for? Should I plug them together?
Had to RMA my ASRock X58 Extreme motherboard back to NewEgg because of a dead memory socket. Waiting for the new one.