A transect is a path along which one counts the occurrences of a phenomena of study. A mega transect is a really long transect. There have been a couple done in recent years, most notably a 2000 mile transect of the Congo Basin in 1999. Utilizing GPS I intend to conduct a mega transect study along the entirety of the PCT in order to map the vegetation and provide a way to track plant migration and vegetation community redistribution in the coming years. When completed, this would likely serve as the longest transect ever conducted by foot. More importantly it would provide a solid data set of the southernmost occurrences and elevation distributions of the majority of the vascular flora of the PCT. While the trail is likely to remain relatively fixed in space, the plant communities surrounding it will surely be on the move. But how much? In what ways and to what intensities? No one really knows. What we do know is that change along the latitudes (north/south) will likely be more severe than longitudinal change (east/west). This is one of the reasons why the PCT, in its north/south orientation is such a valuable asset and a good candidate for a transect. By mapping the location of the flora now we will be in a much better position to understand the coming changes through the decades. Due to the stability and tradition for the trail engendered by the hiking culture, one will be able to hike very nearly the same exact pathway in ten, twenty, or hopefully even a hundred years, and compare plant distributions with the ones we will see this summer. In this way the trail becomes a kind of living time capsule, a classroom in which to better understand ecosystem change through space and time.