One of my favorites growing up but one thing always got me...

It almost seems like a setup for a sequel.

In any case, Cooper got Cap Wilson, the ringleader of the hanging gang. It was by Wilson's directive that the posse went ahead and hung Cooper. Reno and Miller were the two other bad guys who got justice by Cooper. The rest of the guys were almost sympathetic.

And if we watch that scene at the end with Rachel, she asks Cooper why he's keeping up his plan for justice when he asked Rachel to forget hers (the rapists who murdered her husband). Cooper says the end of his journey was in sight, where it was likely she would never get justice.