So I was thinking about true American Heavy Metal bands and it occurred to me that there really aren't a ton of them from the 1970s, at least ones that come to the top of my mind, so I am asking for y'all to come up with some others. I am not talking rock 'n roll bands like Aerosmith either, but true HEAVY F'N METAL! :)

Here is a short list of ones I can think of:
Pentagram (and Bedemon)
Cirith Ungol
Riot
St. Vitus
Trouble
Manilla Road
Legend
Sir Lord Baltimore

We can thrown in:
Blue Cheer
Iron Butterfly


I appreciate your help!