Colorado-Kansas-Oklahoma tri-point

According to the Congressional definition of the boundary of Colorado, this point is theoretically where the 37th parallel north latitude intersects 25 degrees west longitude as measured from the Washington Meridian*. However, the south line of Kansas was surveyed in 1857, and this corner upon it was first located by John Major during his 1872 survey.  Due to the technological limitations of that age, this point is not exactly where it ought to be (although these surveys do define the official boundaries, regardless of their accuracy).  The original sandstone marker is gone now, and apparently there was nothing else at the site until the current plate was installed in 1990.