 However, in October 1767, at Dunkard Creek near Mount Morris, Pennsylvania, nearly west of the Delaware, their Iroquois guides refused to go any further, having reached the border of their lands with the Lenape, with whom they were engaged in hostilities.As such the group was forced to quit, and on October 11, they made their final observations, from their starting point.In 1784, surveyors David Rittenhouse and Andrew Ellicott and their crew completed the survey of the Mason–Dixon line to the southwest corner of Pennsylvania, five degrees from the Delaware River.