@onhwy61: I’ve read about the Mary Martin/Hawks story in a number of places over the years, most recently in a new book I’m currently reading (see below).
Before Dylan even knew about The Hawlks, Robertson and Levon Helm had been hired by John Hammond Jr. for the recording of his So Many Roads album. I think in the movie Once Were Brothers Robertson recounts Dylan wanting him and Helm for the band he was assembling for the 65-66 world tour, and Robertson telling him sorry, he was in his own band, and it was all of them or he and Levon weren’t interested.
The book referred to above is Pledging My Time: Conversations With Bob Dylan Band Members by Ray Padgett (fantastic!). From the chapter with bassist Harvey Brooks (who along with Robertson and Helm had performed with Dylan in the Forest Hills, NY and Hollywood Bowl shows in ’65):
"Mary Martin (Albert Grossman’s assistant) had taken Bob to see the rest of the guys in The Band in Toronto (note: From precious reading it is my understanding that Mary had already seen The Hawks live). He loved it. They decided that it made more sense for them to have a whole band that they thought would fit really good with Bob. So they said to me when I called in ’We’ve made some changes and you’re out. Rick Danko is going to come in from The Hawks (note: along with Richard Manuel and Garth Hudson).’"
Remember, Grossman also managed John Hammond Jr., and I’ll bet that’s how Mary learned of The Hawks, going to see them live (somewhere on the East Coast is my understanding) and subsequently telling Grossman and Dylan about them. She knew Dylan was planning on taking a band with him on the 65-66 tour.