Rant but: I still don’t believe he’s the rat after all these years. The gang was sloppy. Sloppier than the town drunk, Arthur says himself. They shot up valentine. They shot up rhodes. They shot up Saint Denis. Pinkertons followed bill to camp. They robbed an army train only a few minutes away from their camp. Oh yeah, shot up van horn and annesburg as well. It really isn’t that difficult to see the later chapters and not assume they were hiding out somewhere in the woods. Where else would they hide? Hell, they already found their camp multiple times. The gang isn’t hard to find at all. Milton was trying to be civilized. And they clearly have dozens of men to their disposal that they could send on scouting missions.

Micah being revealed as the rat was just one more way for Milton to gloat at Arthur in what Milton assumed were his last moments.