GRAND CANYON NATIONAL PARK — More than 30 bison roaming Grand Canyon National Park's northern reaches are joining a herd in Oklahoma.
Hundreds of the massive animals have made their home at the Grand Canyon in recent years. But park officials say they're spoiling water sources and harming the landscape.
Officials came up with a plan two years ago to reduce the herd partly by corralling the animals and shipping them elsewhere. Thirty-one bison loaded in multiple livestock trailers were shipped to the Quapaw Tribe in Oklahoma on Wednesday.
Several other bison were fitted with tracking devices and released back into the park.
The bison are descendants of ones introduced to northern Arizona in the early 1990s as part of a crossbreeding experiment. The state allows them to be hunted on the neighboring national forest.