[Info from the Official Havasupai Website as of 1/23/2019]

Pack Mules must be reserved BEFORE your visit!

ALL Pack Mules must be reserved in advance of your visit at Official Havasupai Website.

There will be NO Pack Mule reservations done by phone
There will be NO Pack Mule reservations done in person.
ALL Pack Mule reservations must be done online.

Pack Mules (fees are per Pack Mule)
All fees are subject to change without prior notice.
(2019 Pricing)
Between Hilltop Trailhead and Campground Entrance: $400 round trip.
One Pack Mule can carry a maximum of 4 bags and a total of 130 pounds.
Each individual bag must weigh no more than 32.5 pounds.
Maximum baggage size: 36 inches long and 19 inches wide.
Maximum size and weight limits are strictly enforced.
Many people put their backpacks into a duffel bag for extra protection.
Ice chests, coolers, and hard-sided luggage are NOT permitted.
$300 extra for a late run (if you miss the 7AM campsite drop off).

Note: As an option it is possible to transport gear via the Helicopter.  But be aware it does not fly every day.  It is only transported via air between the hilltop trail head, and the village if Supai.   You have to pack it yourself between the village and the campground.  Check on Air arrangements and policy changes prior to your trip.