This project started in June 2007 as a survey for road improvements for the New York Department of Transportation. The survey involved 273 shovel test pits (STPs) in the Towns of Oswegatchie and Lisbon, St. Lawrence County. Three of these STPs were excavated on the property of a historic standing structure in the hamlet of Northrup Corners. These three STPs yielded a total of 37 artifacts, including late 18th through 19th century ceramic vessel fragments. The site was named for Lewis Northrup, shown as the apparent property owner on an 1858 historic map of St. Lawrence County (Rogerson 1858).
Phase II, a site examination, was conducted in September of 2007 with the goal of determining whether the L. Northrup site had sufficient research potential to warrant eligibility for listing on the National Register of Historic Places. Archaeologists excavated four 1 x 1 m (3.3 x 3.3 ft) units, and conducted documentary research into the property's history. The excavation showed soil disturbances at the western end of the site, and as a result, the site size was reduced to 475 m2 (5112.9 ft2). Documentary research indicated that Lewis Northrup had been a wealthy farmer, who had sold the farmhouse at the L. Northrup site to the Maltby family in the 1860s. Artifacts from the site included a variety of historic period ceramics, glass, architectural elements and faunal remains, along with small numbers of other artifact types. Based on the artifacts and documentary record, the site was declared eligible for the National Register of Historic Places.
Phase III was conducted in September of 2008. This phase included 20 excavation units in a truncated area of the site in front of the standing structure, as well as additional historic document research. These units uncovered more of the historic sheet midden (a layer of compacted historic period detritus). A total of 3,955 artifacts were recovered.