Thanks again for the suggestions.
I'm in Canada and can certainly approach the genealogical society in Saskatchewan where most of these people lived. I know there is a Saskatchewan website that links to online genealogical resources and it links to a site that lists cards as well. That is where I got the idea.
A few people whose cards are in the collection were born in or lived for a period of time in the US. Most of my ancestors spent a short period of time in the US before making their way up to Canada. And some of the cards are from family that stayed behind in Germany.
I'll do some more digging and see how I can pair up people who lived in the US with counties and see if I can share some of them that way too.