The claim jumpers go after Walt after he was stealing 10 of their dogs and fur sleeping robes
The claim jumpers start chasing Walt after he was found stealing their dogs. The claim jumpers chase Walt as he tries to go to Dawson. The claim jumpers eventually resort to shooting at Walt with a revolver, but with their distance, they missed their shots. However, the claim jumpers start using a rifle, and shot the lead dog.
This turned out to be a blessing in disguise because the lead dog they shot was bad, leading the others left and right. Walt layed down the bad lead dog and changed it to the good lead dog, who made the claim jumpers even farther. This helped Walt reach Dawson and stopped the claim jumpers, which earned him the title, the King of Mazy May