How To: Territory Zip Code Mapping

Creating a list of zip codes from a map

https://www.freemaptools.com/find-zip-codes-inside-user-defined-area.htm

It's a little clunky to use, but you can draw a polygon on a map, choose the state you only want to include, and get a comma-separated list of zip codes.

Here's a quick Southern California example.

Draw the polygon roughly around the area (you just click once at each point, no dragging):

Click the Search for ZIP Codes button

Remove unwanted States:

Copy the list of zips to your clipboard