GRAND CANYON NATIONAL PARK, Ariz. — Grand Canyon National Park officials said they have been overwhelmed by the interest in a program to thin a herd of bison using volunteer shooters.

The National Park Service approved a plan last month to decrease the herd through roundups and by seeking volunteers who are physically fit and proficient with a gun to kill the animals.

Park officials said the roughly 600 bison in the region increasingly were damaging park resources.

Grand Canyon officials bombarded by interest in herd-thinning program

Grand Canyon officials bombarded by interest in herd-thinning program

Grand Canyon spokeswoman Kirby-Lynn Shedlowski said she initially received dozens of calls a day from people across the country offering their skills.

Callers were directed to a recorded line and asked to check back periodically.

The park, state game officials and the Intertribal Buffalo Council were expected to meet this month to begin crafting program guidelines.