Can you hide a drive from steam?

[Anachronda]

I have a slow mechanical removable usb drive I use for archiving data, backups, or otherwise relieving my other drives. Because of this I don't want my steam games installed on there *ever*. But steam keeps putting a library there. I deleted the library from it, but every time I install a game one of the choices is to create a library on that drive and install. Right below the option I *do* want.

I don't get it. I never had this before. I have other drives that don't show up, including another exactly like this one. How can I remove this drive from the rotation and stop this madness?

[Haruspex]

I have a similar external mechanical drive I use for cold storage. It's actually a big internal SATA drive plugged into a USB dock. That dock has a power switch, so I just leave it off when I'm not using it.

If you don't have a power switch, you can physically disconnect the drive when you aren't using it. Otherwise the only other option would be to just not click that drive by mistake when you're installing games.

[Zukabazuka]

Go to Steam settings and then go to the storage tab in there. Steam will keep adding the folder to that drive as long as it is added to that list. Then just delete it from the storage tab.