trail angel
n. A person who leaves food and performs other acts of kindness for hikers.
Wren experiences awesome vistas and starry skies, pelting rain, sore knees and a night in the hospital with a possible tick bite. And he witnesses miracles: a woman who bakes chocolate-chip cookies just for hikers, a shop that offers hikers free milkshakes and — most wondrous of all — "trail magic": the rare sighting of a can of beer left chilling in a stream by a "trail angel."
—Carol Peace Robins, “Books in Brief: Walking to Vermont,” The New York Times, April 11, 2004
From Springer Mountain in Georgia to Maine's Mount Katahdin, Pegg enjoys a rock star's renown. The 59-year-old retired prison guard from Sussex County … is a "trail angel."

During the nine-month hiking season, he distributes "trail magic" — free water, food, and other goodies - just about every day to through-hikers traversing New Jersey as they attempt to walk the entire 2,172-mile Appalachian Trail.
—Bob Ivry, “An angel through and through,” The Record (Bergen County, New Jersey), August 21, 2003
1994 (earliest)
Trail Angels and Trail Magic (chapter title)
—Larry Luxenberg, Walking the Appalachian Trail, Stackpole Books, October 01, 1994