The following pages are on the Kumanago website. The first URL takes you to an English page. The second URL takes you to a Japanese page. Even if you are not very good at Japanese, you might want to give the Japanese page a try because the clickable map takes you to pages, with Google maps to show exact locations, about many more hot springs. If you like onsen, one strategy might be to just click on a place near your home or a place you are planning to visit and then go there to see what it’s like.
I should point out that the Google maps are embedded in a way that makes them difficult to use. Once you get to the page with a map on it, you might just copy the Japanese address (toward the top of the page) and then paste it in a Google maps search. That will give you a map that will allow you to zoom in and out on as you please.
http://kumanago.jp/en/spots/search?keywords=&genre_id%5B4%5D=4