Hunters have killed more wild bison migrating from Yellowstone National Park this year than they have in decades.
    
Driven by strong participation from Native Americans, roughly 250 bison have been killed after leaving Yellowstone for low-elevation winter range in Montana.
    
Tribal and state officials said Friday the hunt results should provide some relief for the park's burgeoning population of the animals.
    
That means there's unlikely to be a repeat this year of the wholesale slaughters that have killed thousands of bison over the last two decades in the name of disease control. Officials say a limited slaughter is still possible.
    
The tribal hunts, conducted under long-standing treaty rights, are expected to continue through the end of March.
    
State-licensed hunters took 37 bison during a season that ended Feb. 15.