Related Clues:

• Source of a thundering sound
• Crowd
• Cattle that all have the same brand
• Moving stock
• Round up
• Driven animal group
• Stampede group, maybe
• Savanna group
• Bison bunch
• They're rounded up in a roundup
• Drover's group
• Guides
• Cattle cluster
• Heads for the ranch?
• Plain sight