exploretheline.com presents:

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Nov. 23, 2008: A new marker along Mill Run Road east of the Youghiogheny; a new view of a previously visited marker along Mine Road west of the Cheat River.

Aug. 18, 2008: A new marker added to the list -- south of Point Marion, Pa., and east of U.S. Route 119.

May 15, 2008: Travel with me as I explore seldom-seen corners of the area. Read my writings and other musings.

April 15, 2008: exploretheline.com goes international! Read the article by Lynne Hall in the UK's Teesdale Mercury.

Audio report!

March 3, 2007: Hear my observations while walking along The Line at Lake Lynn Dam that holds back the waters of Cheat Lake. The dam sits several yards into West Virginia.

What's all this "line' talk about?

The Mason-Dixon Line, surveyed by Charles Mason and Jeremiah Dixon from 1763-1767, effectively is the southern border of Pennsylvania (though Mason and Dixon also surveyed the western border of Delaware).

I call The Line between West Virginia and Pennsylvania "the forgotten frontier." While a great deal of information is available about the segment of The Line between Pennsylvania and Maryland, little is written about the "forgotten frontier," the Mason-Dixon Line between the Keystone State and West Virginia, which was born in 1863.

Did you know that travelers on Interstate 79 crossing the state line between Monongalia County, W.Va., and Greene County, Pa., see no indication they've crossed the Mason-Dixon Line? And in other locations, such as U.S. 19 north of Morgantown, there are few historic markers heralding what might be the most-famous border in the U.S. So how was this 18th-century work done? Mason and Dixon surveyed the line using ASTRONOMY!!

The western end of the Mason-Dixon Line was resurveyed by Cephas Sinclair from 1883 to 1885. The markers you may find on The Line were placed during this resurvey.

The Cornerstone Area: the western end of the Mason-Dixon Line

Why do I call Pennsylvania's southwest corner "the end" of the Mason-Dixon Line even though Mason and Dixon never got here?

It's because it's HERE they were headed.

While Indians stopped Mason and Dixon's survey in October, 1767, a team headed by David Rittenhouse and Andrew Ellicott completed The Line to the southwest corner of Pa. The Cornerstone (placed in the Cephas Sinclair Resurvey of 1883) is 5 degrees in longitude from the Delaware River -- which is the distance that was awarded William Penn in his charter of 1681. No Mason and Dixon-related surveying was done westward beyond this point even though an "extension" serves as the border between Wetzel and Marshall counties in West Virginia. The Missouri Compromise of 1820 led to the general perception that the Mason-Dixon Line runs through far-off states such as Illinois. It does not! The actual surveying of The Line ended at the southwest corner of Pennsylvania. From there the Rittenhouse-Ellicott team began the survey of Pennsylvania's western border -- the Ellicott Line.

  • That's me at The Cornerstone, the western end of the Mason-Dixon Line

  • See a topograpic map of the location of The Cornerstone from topozone.com. Take note of the stone plotted to the north of The Cornerstone on the Ellicott Line and the Penultimate Stone just to the east of the corner.

    Site last updated Feb. 27, 2016. Photos copyright Pete Zapadka. Some photos by Colleen Nelson.

    A special thanks to my inspiration, Amy Johns, for whom I'll always cross The Line! Check out Amy's beautiful handmade jewelry.

    Don't forget to use the JUMP STATION, below, to access the other pages at the exploretheline.com. Thanks so much for visting my tribute to the work of Charles Mason and Jeremiah Dixon -- All the best, Pete.

    The last crossings (near Ned, Pa.)
    Near the real end of The Line
    From Ned to U.S. 19 and I-79
    Near Mount Morris, Pa., and Morgantown
    Brown's Hill
    (Mason and Dixon's westernmost site)
    The Dunkard Creek crossings
    (where Mason and Dixon were stopped)
    From U.S. 19 and I-79 eastward
    To Chestnut Ridge
    Lake Lynn Dam
    It forms Cheat Lake
    West of The Line
    If it was extended west to the Ohio River
    Easternmost Western Crossings
    Random crossings east of Chestnut Ridge
    The Tripoint
    Where W.Va., Md. and Pa. meet
    The Transpeninsular Line
    Delaware's southern border
    Delaware's southwest corner
    Another end of The Line
    Mason-Dixon markers I've visited
    Some are out of the way
    Coming soon

    Coming soon

    To come: The Ellicott Line
    Along Pa.'s western border
    Back to the main page
    The starting point
    Highways that cross The Line
    State and U.S. roads, Interstates
    Links page
    See what else is out there