thru-hiker 

One who hikes a hiking trail that takes a month or more to complete. The hike is not necessaily done without leaving the woods or path. Trips into town to resupply, shower and rest up are accepted and sometimes necessary.
The term end-to-ender is applied to one who hikes the entire Vermont Long Trail in one trip, but they are also considered thru-hikers.
Section hiker is one who hikes the same trail, but completes it over a period of years.
Leap frogging is someone who does not hike the trail in one straight line, but rather jumps ahead, via hitching a ride and may or maynot return later to finish the section they skipped.

Some who hikes the 2,160 mile Appalachian Trail that goes from Georgia to Maine within one year is a thru-hiker. Also some one who hikes the 2,650 mile Pacific Crest trail or the 3,000 mile Contintial Divide Trail within 12 months are also considered thru-hikers.

thru-hiker by Dana Lemieux August 27, 2006