A person (male or female) who enjoys hiking, canoeing and other outdoors-y things. They often can be seen drinking out of a Camelbak, wearing tie-dye, wearing Chacos, and eating trail mix. They're the type of people you see hiking in the mountains of the United States or backpacking across other countries for long periods of time.
My sister is a professional camp counselor. She runs the hiking classes-- she is such a granola girl.