I saw Gordon Lightfood 3 or 4 times in the 70's an 80's. I fell in love with Folk when I was 14 years old... about 1971.
Others on my list:
Hoyt Axton
Tom Rush - I saw in concert in Seattle in 1988 in a small venue
Arlo Guthrie
Simon/Garfarkle
Mason Williams
Judy Collins - one of the purest female voices I've ever heard
Joan Baez