Hiking the Appalachian Trail 

Euphemism for sticking it in the butt of an Argentinian woman.

Governor Sanford (R) was furiously hiking the Appalachian Trail for several days over Father's Day weekend.

Hiking the Appalachian Trail by ZezAzeZ June 24, 2009

Hiking the Appalachian Trail 

To have an extramarital affair in another country, especially South America.

South Carolina Governor Mark Sanford was hiking the Appalachian Trail last week and didn't tell anyone where he was, but he's really really sorry about it.

Hiking the Appalachian Trail by Ken Starr June 24, 2009

I was hiking the Appalachian Trail. 

Made famous by South Carolina Governor Mark Sanford, it's a euphemism for when you're doing something nefarious.

Randy: Hey, were you out messin' around with that tranny again?

Daryl: Nah, dude. I was hiking the Appalachian Trail.

I was hiking the Appalachian Trail. by Butler CW June 24, 2009

Hiking in the Appalachian Mountains 

Claiming you are going "Hiking in the

Appalachian Mountains" for vacation when in fact you are going away for a booty call.

Bob: Yeah, I'm burnt out. I'm going Hiking in the Appalachian Mountains for some R&R.

Frank: Dude, who are you kidding. I saw you and Sally from the copy room groping each other in the bar. You're headed to a Motel 6 for a few days

Hiking in the Appalachian Mountains by Langbo June 25, 2009

Hiking the Appalachians 

To "hike the Appalachians" is to cheat on your significant other.

Politicians love stealing our money and hiking the Appalachians.

Hiking the Appalachians by noncoercive June 24, 2009

Hikin' the Appalachian Trail 

Cheating on your wife or girlfriend, especially if in the process of cheating, you disappear for a few days and say you are going someplace where it is impossible to be reached. Can also be used on a woman to say that she's cheating.

Same meaning as the other two entries here at UrbanDictionary.com: "Hiking in Appalachia" and "Hiking in the Appalachian Mountains", except that that "hikin' the Appalachian Trial" sounds better.

guy 1: "Where's Dave? I thought he he was going to play golf with us today."

guy 2: "He told his wife he had to work the weekend, but I think he's hikin' the appalachian trail. He was flirting all week with that new chick in accounting"

-or-

guy 1: "Where has your girlfriend been lately?"
guy 2: "I dumped her ass! Caught her hikin' the appalachian trail, and that was it for that slut!"

Hikin' the Appalachian Trail by rpompeii June 29, 2009

hiking the Applachian trail 

cheating on one's spouse

She thought he was away on business but he was actually "hiking the Applachian trail" .

hiking the Applachian trail by AZAFVET August 20, 2009