How did Morris come to know about Birdy Edwards?

Morris received a telegram from a friend who worked in the telegraph office, alerting him to Birdy Edwards presence in the Valley.

This was what McMurdo read:
How are the Scowrers getting on in your parts? We read plenty of them in the papers. Between you and me I expect to hear news from you before long. Five big corporations and the two railroads have taken the thing up in dead earnest. They mean it, and you can bet they’ll get there! They are right deep down into it. Pinkerton has taken hold under their orders, and his best man, Birdy Edwards, is operating. The thing has got to be stopped right now.