A copy of They Made Their Mark: The Society of Women Geographers is up for sale on ebay.
I'd done a search on Fay Gillis Wells, pioneering woman pilot, and then scrolled down at all the other "similar" offerings that eBay always gives you.
It was established in 1925 by Gertrude Emerson Sen, Marguerite Harrison, Blair Niles and Gertrude Mathews Shelby
They founded it because of course women weren't allowed into the men's clubs of the day. As a matter of fact, the Explorer's Club didn' admit women until 1981.
The Society of Women Geographers today only has about 800 members - which is sad. There's got to be more than 800 women geographers in the world!