Jeff, this may be your answer:
https://github.com/Jorl17/open-eleva...er/docs/api.md
It's a public/free API for elevation queries. Examples are there to call it from curl, but obviously you could easily make a Python script/whatever to send queries.
For instance, in a web browser:
https://api.open-elevation.com/api/v...23826,1.317397
Response:
{"results": [{"latitude": 51.138584, "elevation": 105, "longitude": 1.366985}, {"latitude": 51.123826, "elevation": 7, "longitude": 1.317397}]}
The first set of coordinates are the cliffs to the eastern side of Dover port, returning a height of 105 metres.
The second set of coordinates are also Dover near the sands/seafront shopping area, returning 7m.
The API does respond quite slowly unfortunately (at least for me), so that might be a limiting factor.