During roundups in rough-county, some cattle get very savvy about escaping from the cowboys. They get smart and hide out when they see or smell any riders. After a few years the ranch often has five or six, 4 year old bulls, big unbranded calves, wild cows and steers, all who have learned to stay away from the ropes of the ranch hands.
Cows, calves and bulls which have not been branded and earmarked are called “Mavericks”. Steers are bulls that have been cut and branded, but have escaped and grown dangerously large.
This cow hand has jumped a bunch and is Chasing these Mavericks them in hot pursuit.