Stampede

 I think this is probably based on the New Forest ‘Drift’ which is the annual round-up of the ponies on the Forest for a health check. The Commoners ride like characters from the Wild West and with great skill herd them together. It is very dramatic. However the ponies and riders at the front in the drawing are not as urgent as the ones further back so I’m not sure what’s going on. And Richard has transposed the scene to a Yorkshire environment with some mills in the background with a possible hint of a rainbow.