Here’s something you may not have known: the length of the Appalachian Trail changes pretty much every year.

I learned today via Facebook that the official AT distance for 2015 is 2189.2 miles. (That’s 3523.18 kilometers.) I believe the 2014 official distance was 2185.3 miles.

The additional 4 miles didn’t come from some kind of continental drift.

The thing is that there are almost always relocations, and it just seems that they always add a little distance to the whole length. For years the Trail would be moved bit by bit off of private land onto public (say, National Park Service, or Forest Service, or State Park) land. Or maybe a section just gets over-used into erosion and so the official pathway gets moved to let the original trail go into restoration mode. Or perhaps instead of aiming steeply straight up a hillside, the maintainers decide it’s time to change that climb to an easier grade by using switchbacks (zig-zagging). Or sometimes the Trail is moved to get it away from something that gets built right up on the Trail’s property line.

A couple hundred yards here, a quarter mile there … before long you’re talking 4 more miles.

Anyway, you can start the betting pools now. If a hiker starts at one end on 13 April, what day will he get to the other end now that it’s 2189.2 miles away?