I bought my initial pair Brooks Cascadias a little big (13 instead of 12). I kept that size for the duration of the hike. I ordered new pairs from REI along the trail: mailed to Daleville (VA), Vernon (NJ), & Andover (ME; barely held together w/ duct tape). REI shipped by UPS so no General Delivery PO addresses (made that mistake on a shirt; took me a couple of weeks to catch up with it).