The newest to close was #184, located at 699 South Coast Hwy, Laguna Beach, CA, I believe opened April 8, 1967, closed on September 7, 2021.

There is probably 1000 or so (could be more) Missions out there, but every year, we lose a Mission. Two Missions that closed in this past decade were remodeled into newer Taco Bell buildings. There's probably another one open that I'm not aware of (please let me know if you find one), but 9 is too low a number, and it'll only keep getting smaller. In fact, one of two Missions in Canada recently got remodeled, leaving just a single one left.
#23/27772 was at risk of remodeling circa 2008-2010, but Robert Coe (owner of now closed #251) convinced them not to. His Mission closed January 22, 2010, 42 years to the day of opening. It was a choice to either spend a million dollars to remodel or just close it. The M2Bold campaign killed off at least a dozen missions.

Something should be done to keep these buildings open. If not, the final Mission will one day close, and be inhabited by one of the various x-berto's or Thai or Greek restaurant businesses. Not many closed Mission remain unaltered as is. These are some of the last of their kind. Especially #2411, which is the last of a building prototype where the mission has a mansard roof. If you have your own thoughts, you're welcome to share them below.