Your best bet is to contact a horse packing firm (try googling, there are lots!) to bring your resupply in. They do a lot of this! Your google search should focus on the trailhead the packer will use. If your resupply is in a popular area, you may be able to piggyback on someone else's trip, which would be a lot cheaper. For example, at Island Lake you'd be quite sure to find a piggyback situation. Getting resupplied in a location where the packer can go to your pickup location and back home in a day will also be cheaper. If the packer has to stay out overnight, or make a special trip just for you, it will be a lot more expensive.
The guidebook Beyond Trails in the Wind River Mountains, by our very own Wandering_Daisy, discusses this (along with lots of other logistics) in the last chapter. I haven't seen her post here lately, so I suspect she's out backpacking! Otherwise I'd have left this question for her to answer. I researched this about 5 years ago but didn't get very far (the location I was considering was quite isolated and a long way from the trailhead). .
Edited by OregonMouse (07/15/16 07:32 PM)
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May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey