Michael Green
Browse magazine works (first published 1974)
indicates that this is the same author as <a href="https://www.isfdb.org/cgi-bin/ea.cgi?266256">Michael Green (artist)</a>. The author has verified through email that while the biographical details in Locus1 are correct, he is not the author of the horror novels indicated under this author. The about the author note for "River of Stone" notes that this author lives in New England.