Get in communicationa with the "Trans-Canyon Shuttle" to send yourself resupply for on your middle-section rim rest (the rim you are planning on not starting and finishing of). You can also use U.S. Postal mail, but read guidelines for general deluvery and follow directives, because the U.S. has been losing it's "General Delivery" program from mal-use? You can also spend a lot of money in the concessions, or use the hospitality industry as a checkpoint. That aspect is private-sector and abiding by their policies is also essential. Non-demand obligation to provide business prospect rests on the shoulders of the recipients and is the only way such allowances are kept viable. (And, often enough, it is not viable due to overuse, misuse, and disuse; so, don't make expectation and any of your better anticipation would follow through).