Toward Ecosophy

One of the plot engines in my about-to-be-released novel The Weird of Hali: Chorazin is a folk song, "The Sleeper in the Hill," that includes certain clues that the characters have to follow to make sense of the mystery hidden beneath Elk Hill in far western New York State. I had no trouble hearing the words and the melody of the song, but my musical chops fall short when it comes to finding the chords. It's a modal melody, and I'm pretty sure it begins and ends with an A minor chord, but beyond that I have no idea. Help from my musically literate readers would be greatly appreciated. Here are the dots: 

Thanks to anyone who can help!