Denney earned a Bachelor of Fine Arts degree with honors from the Art Center College of Design. After graduation, he worked a few years in Culver City, California, with the Hughes Aircraft illustration group and later with Filmation Animation Studio in Reseda, CA. Denney and his wife Linda then moved to Red Lodge, Montana, where Denney assisted Stan Lynde for six years producing the cartoon strip, Hipshot and Rick O'Shay. In 1976, he began spending more time painting landscapes and teaching painting workshops. In 1982, he was awarded Best of Show at the C. M. Russell show and the Artist's Choice Award at the Buffalo Bill Show in 1997 and 2005. Recently he published a book of cartoons and imaginative stories about artists. The book's title, Burt Umber, reflects his sense of humor and interest in drawing.