Tom Russell:

Cowboy Real
Rose of the San Joaquin
The Man From God Knows Where
Indians Cowboys Horses Dogs

Ian Tyson:

Cowboyography
And Stood There Amazed

Utah Phillips:

Good, Though
Loafer's Glory (w/Mark Ross)
(or just get the 4-CD set, "Starlight on the Rails," and be done with it)

Almost anything that you can find by Mary McCaslin and/or Jim Ringer.

Almost anything that you can find by Guy Clark.

Peter.