Oh, to the NW of Riverton is Dubois (pronounced "dew-boys"). That is the place that Jack and Ennis ate a meal together before, according to the published original story, they drove off in opposite directions. It was after leaving Dubois that Ennis thought he had to puke since it felt like someone was pulling his guts out.
Real compassion for a person comes from the lower gut. It is a very deep-seated emotion.
Also, in Annie Proulx's story, Brokeback Mountain and Signal were near Dubois. There is a "Signal Mountain" on up the road past Dubois above Moran, Wyoming. "Signal" could have just been a "wide place in the road" near Dubois. And, it's name could have come from the fact that "signal" referred to a railroad signal at a rail crossing. At least, there is a railroad in the movie where Jack and Ennis first meet.