45,000 people sign up for a chance to kill 12 bison in the Grand Canyon

The National Park Service says in just 48 hours, 45,000 people signed up for an opportunity to kill 12 bison in the Grand Canyon.

The parks service opened up the hunting application because it is concerned with the growth of a bison heard in the North Rim area of the Grand Canyon, according to a news release.  The herd may impact water, vegetation, soils and archaeological sites in the park and "reducing the herd size will protect the park ecosystem, resources and values," the park service said.