There are two free Wi-Fi spots in the vicinity: Welcome shelter on the way to Hammersley Gorge (-22.255797, 117.980331) and the rest stop on the corner of Karijini Drive and Great Northern Highway (-22.667711, 118.699239).
Phone reception towers have been installed in the National Park at three locations, the Karijini Eco Retreat, Karijini Visitors Centre and Dales Gorge Campgrounds. The Mt Bruce car park also has good reception for some carriers. Telstra and Optus tend to get the best coverage but cannot be guaranteed.
There is no ATM in the Karijini National Park and we strongly suggest bringing cash to this event. The Karijini Visitors Centre and the Karijini Eco Retreat have EFTPOS facilities for their products and services. The Karijini Experience has some EFTPOS facilities available during the event for ticket and merchandise sales only and will accept cash payments as well. Note that communications can be unreliable in the park so we suggest bringing cash.