Thirty-one bison captured on the North Rim of Grand Canyon National Park are heading to Oklahoma, where they are being given to the Quapaw tribe.

The bison were shipped off Wednesday to the InterTribal Buffalo Council, which took them to Oklahoma. The transfer of the bison concluded the Grand Canyon National Park's pilot program for corralling and relocating bison from the North Rim.

"It's an historic moment. These are the first bison ever captured and permanently removed from Grand Canyon," said Grand Canyon Bison Project Manager Miranda Terwilliger.

Leading up to the capture operations, a corral was regularly supplied with food and water to encourage bison to enter freely and increase their exposure to humans.

"It's a passive process. You want to work as quietly and calmly around the bison to keep their stress levels down because they have very little interactions with humans," said Chris Clark, the South Rim lead mule packer who served as the corral boss.

After a large group of bison entered the corral during the operation period, staff closed the corral gates and began processing them in preparation for shipment. The processing included separating and releasing bison that were too young or too large or old to make the trip. They were guided into a squeeze chute, where the scientists took blood and genetic samples and tagged them per U.S. Department of Agriculture shipping regulations.

"We had an amazing team who worked really well together," said Terwilliger. "We did a lot of mock runs and training in advance with other parks and agencies."

Biologists from the Kaibab National Forest, Yellowstone National Park, Badlands National Park, the U.S. Geological Survey, and the InterTribal Buffalo Council assisted. Also present was a National Park Service veterinarian to oversee the well-being of the bison.

Several additional animals were outfitted with tracking collars and released during the corralling process. The collaring was conducted with the assistance of U.S. Geological Survey scientists for park wildlife biologists to study the bison migratory patterns and population size.

The goal of the pilot program was to capture and relocate up to 100 bison. The pilot program was conducted this year due to the bison migrating to a warmer location on the North Rim from early snowfall last year. There's approximately 600 bison on the North Rim, and Grand Canyon National Park is reducing the size to under 200 over the next three to five years to protect park resources from the impacts of the bison population.