I gather that once , if not still, there was a restaurant run by this couple.
Not so much a restaurant, Clair, as an outfitting establishment.
Although it's long since folded, Herter's was the Midwestern equivalent of L.L. Bean. And had started the same way. George Herter was an avid outdoorsman who couldn't find the kind of gear he wanted. So he started to make it. Next thing you know, he's got a great thing going.
Many of the recipes in their cookbook are based on camp food, and on food they enjoyed in hunting & fishing lodges.
When it comes to the Church, Grange, and Organizational cookbooks, the best part of them is, once you're past the Campbells soup and Jello mold stuff, the regional nature of the recipes. Browsing through those books you are sure to find recipes for things you never heard of, unless you're from that region.
Similar are the cookbooks in which the authors go out and collect recipes from real people, instead of food professionals. Nancy Davis and Kathy Hart's Coastal Carolina Cooking is a great example of this. Perhaps the ultimate in this genre would be Alford and Duguid's Flatbreads & Flavors, because of its global nature.
And let's not forget the world of self-published cookbooks. Sure, many of them are crap. But more and more we're seeing some really good ones. Sandra Bowen's Spiced Right, comes to mind. And many would include my own A Colonial Virginia Book of Cookery" in that category.
I'm surprised that nobody seems to have mentioned the remaindered table at bookstores as a source. There are some great bargains available at those tables, often on cookbooks you might never have heard of otherwise. One that comes to mind, that I found that way, is Victoria Wise's Gardener's Community Cookbook.