Charro is a horseman and Charra is a horsewoman? Something like that.
These Charros march in the 16th September parade, to commemorate independence day. Charreria has long been practiced in Mexico and is all about horse reining, heeling, steer tailing and acts like bull riding, team roping, bareback on a wild mare, forefooting, forefooting on horeseback, the pass of death and Escaramuza (skirmish) which is “an event for teams of women who perform precision equestrian displays riding sidesaddle and garbed in Adelita dress.”
By the way, anybody remembers Elvis Presley in the film Charro! back in 1969? (not me, but I have heard of it)