The Red Cadre were a group of "land pirates" led by Hatchet Jack who used prairie schooners to raid settlements in Wyoming and South Dakota. Hatchet Jack was killed and they were largely wiped out during a failed attack on Amicus. (Demons of Eden)
They used to use the ville of Amicus as a base to winter in, until they attacked a native group. They were then forced to leave and not return. But when Ryan and his band attacked them, then took an ancient map, the Cadre followed them back to Amicus and attacked. They nearly succeeded in destroying the ville, but were in the end beaten off by Ryan and his friends. Their leader was shot to death by a woman he had captured earlier, a woman named Felicity. She is in turn killed by him. The few surviving members of the Cadre are wiped out by Touch the Sky's men.