Q: how do you hide the gray bookmarks/reading list bar on the left side?

From your Safari menu bar click View > Hide / Show Reading List or Bookmarks Sidebar.

emmcintosh,

Click on the small "book" icon just below the left (go back) arrow in the upper left side of the Safari Menu Bar.

This opens and closes the bookmarks…

Hope this helps, Greg

This helped me too, trying to close bookmarks on the iPad. Why is a book used to represent bookmarks!? Apple used to be so good at communicating, not many versions of OS X and iOS ago.

but for me the bookmark icon seems disabled.  And I have a stack of untitled folders I can't figure out how to delete.  I never should have purchased this ****.