This is 99% invisible. I'm Roman Mars.

There are currently more than 31,000 post offices in the United States.

There are grand old ones that take up entire city blocks,

and there are smaller humbler ones

hiding away in the backs of general stores in towns across rural America.

But this one in Arizona may be the most rural post office in the continental US.

The Supai Post Office is located at the bottom of the Grand Canyon.

That's Vivian Campbell.

My name is Vivian Campbell, and I am the postmaster of Peac Springs, Arizona.

Vivian works closely with the Supei Post Office, and she says there are only a few ways to get mail

to the bottom of the Grand Canyon.

You either have to hike down there, ride a mule, or ride a horse.

And so every day, rain or shine, mail gets packed on 10 mules to make a 2.5 hour trip into the canyon.

The post office is there to serve the people who live on the Avasupi Reservation.

Avasupai Reservation.

Ava soup pie meaning blue-green water people,

named for the waterfall at the bottom of the canyon.

The falls are just magnificent.

The water is so blue, it's not even, it's indescribable. The office

who pie receive a lot of food supplies but otherwise their mail is pretty

standard fare. They get packages from Amazon they get first-class, they get bills just like you and me.

The Su-Pai Post Office was established in 1896, and its existence speaks to the links

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