Somewhere west of Lehigh County on a rural stretch of Interstate 78, the Shorti ceases to be readily available and the MTO takes its place as the convenience store sandwich that can perhaps be most conveniently acquired.

Wawa, a Philadelphia area institution that for decades has been a popular convenience store chain in the Lehigh Valley, still has a stronghold on the region, but there's been some infiltration in recent years by Sheetz, which has long had a grip on central and western Pennsylvania.

But where exactly does Wawa country end and Sheetz country begin? This interactive map points to a front line somewhere in Berks County. The yellow dots represent Wawa locations; the red ones represent Sheetz locations. Click on the dots to get the address. Zoom in to get a closer look at the breakdown in any region of the state.

Both chains have a following: Wawa's signature hoagie, the Shorti, is arguably one of the most popular local lunch options for those on the run. Sheetz diehards would argue its MTO Subz are far superior.

The Lehigh Valley is now home to three Sheetz locations - Route 248 in Palmer Township, MacArthur Road in Whitehall Township and Schoenersville Road in Bethlehem.

Wawa has more than a dozen locations in the Lehigh Valley, including stores within a mile or so of the three Sheetz locations.

The numbers tell the story: This is still Wawa country.

But, as the map shows, by the time a carload of Wawa loyalists travels as far west as Harrisburg, finding a Shorti would likely require them to refuel at a nearby Sheetz. They might even have to get an MTO while there to tide them over.

Nick Falsone may be reached at nfalsone@lehighvalleylive.com. Follow him on Twitter @nickfalsone. Find lehighvalleylive.com on Facebook.