not next to a city? no problem
check for a local buyer club
http://www.agrilicious.org/home
or a local farm.. some of them do sell feeds
as for order online.. i looked into this place but since i have local stores here.. the shipping cost made no sense to me so i didn't go through with it
but it might be ideal for you.. since they do offer shipping discount once in a while.. and also by visiting their site (if provide new email each time) they will you a free shipping code on certain items (NOT FOR FEEDS though:/)
http://www.groworganic.com/country-living/chickens/organic-chicken-feed.html
wow.. 250 miles from the city? do USPS/UPS/Fedex/ DHL deliver packages that far out?..