It doesnt get much more Arizona than this: Amazon says mules are helping deliver packages all the way to the bottom of the Grand Canyon.

The four-legged delivery team members have long provided rides in and out of the canyon, as well as supplies for those in Phantom Ranch. They have since also become mail carriers and delivery partners.

Amazon says its deliveries are only available to the Phantom Ranch employees who live and work there. Those employees also order supplies for guests and hikers.

According to an Amazon blog, the packages are delivered four days per week, and the delivery process begins before sunrise so they can avoid the heat. The mules descend miles into the canyon to the Phantom Ranch area, which is only accessible by foot trail or via the Colorado River.

The Grand Canyon is one of the “most unique” places Amazon delivers to, which also includes areas of the Himalayas via motorbike, in North Carolina via helicopter, and in Michigan via horse.