Email sent with all relative info. I'll copy it here for future reference in case anyone else wants it. I don't think yogi will kill me for copying one town stop out of the guide.
As far as the resupply. Mammoth has a general post office which is free apart from postage to mail to (I'm dropping mine off on the way up to start my JMT hike with a friend). It's an easy hitch into town, or there's a bus for a nominal fee. Very well traveled road (I'm up there often so I'm familiar with it), and it's a pretty short hike out to it as well. Once in town there's a number of outdoor stores that will sell every kind of fuel you can imagine as well as a gas station to pick up heet, and a hardware store to pick up denatured alcohol. You can mail fuel with usps, as long as it's declared, and you ship it ground, and you package it right. The post office in town is also well aquatinted with hiker boxes because of all the JMT/PCT hikers that come through, so it's nothing unusual for them.
and since I happen to have the pct guidebooks with me because I'm planning everything for next year
Bus from reds meadow (no hitch required) will take you to the mammoth ski resort 7$ and runs every 1/2 hour from 7-7. Catch a free bus from there into town from there, and then a free trolley to get you everywhere around town
or take the side trail from reds meadow to mammoth lakes. Take the 1.7 mile side trail towards horseshoe lake. You can hitch in from there rather than paying the 7$ shuttle fee each way.
3.8 miles before the reds, leave the pct, walk a 4.9 mile side trail then catch a ride into town
Post office: 760-934-2205
mammoth lakes, CA 93456
Post offices are required to hold packages for 10 days IIRC minimum, and many will hold it up to 2-3 weeks if you have an estimated delivery date on there.
They have a full vons supermarket if you don't want to mail stuff ahead (very easy to get just about anything here, and it's decently cheap)
Outfitter: (among many in town)
mammoth mountaineering supply
Motel six is very hiker friendly:
will hold packages if you decide to stay here
showers are available across the street from the campground or for free back at reds meadow (though questionable on the heat as they come from the hot springs)
shady rest campground across from the mcdonalds near the south (only) entrance to town
Schat's bakery is worth a stop if you want some amazing pastries/bread/etc
it's on main street just north of footloose. You can't really miss it, as it's the only real street in town
heet at napa auto parts
Denatured alcohol at do it center