Population, 500.



Well, he MIGHT be here. He's almost certainly not here. But.......

And this is almost certainly not true....

The Monument Day banner names three communities affiliated under the CRM 3-ring symbol. One of them is apparently named "Portland".



If Michonne headed North up the Chesapeake Bay, and then kept going on foot, the tip of the bay points almost directly at Portland.................

Portland, Pennsylvania. Population 500. [The red pin below].



There is also a Portland, NY, and in A World Beyond the kids are holding a map of NY in one of the teasers and it is implied that this is where they are headed to find their father. So maybe he's in Portland, NY, which is also north of the Chesapeake.



So Rick is ALMOST for sure NOT in Portland PA or NY.