The Mules pass through our area quite often. I've never managed to see them in person, but one of the speakers for my riding club last year is the guy that's doing the documentary on them.
He's only got 2 mules right now, I think that Belgian/Haflinger colored one had an accident and had to be put down, he was borrowing a dark brown mule for a bit, but I think she went home, and Lady has to be retired soon, and Little Girl is probably nearing that point as well.
I follow the story on Facebook. They seem to be staying put for a bit near Bakersfield. I suppose John has to make some decisions about what's going to happen with the two old girls.